I'm making myself really unwell over my apprenticeship

I've been reading a few advice threads for a couple of days now in the bid that it will bring me to some form of conclusion on what to do about my apprenticeship. I'm 18 coming up for 19 rather soon, i've re-sat my ASlevels twice and realised that school just wasnt for me, and so I left in the hope of finding an apprenticeship, eventually settling for dental nursing, the journey to work became tedious some 40 miles for a round trip to the first practice I was placed in, I got comfortable with the people there and began to just get on with the job without really thinking about the effect it was having on me (although the dentist I worked with was completely horrible to me). After 6 months I decided to ask for a transfer closer to where I live which was accepted, I had high hopes that it would be a new beginning, however I was slightly de-railed before starting as my Grandma died the day before I was due to start, i'm not too good with handling new situations as is so admittedly that put my metaphorical footing off, the managers been really nice about the situation but shes not aware how i feel about the job itself, im not so sure wether I havent allowed myself to adjust or if how im feeling is completely job based nausea and worry, its gotten so bad that the doctors signed me off work with stress, i've been working myself up so badly i've been physically throwing up over the thought of going back. Why do I hate it? I can honestly say the building just makes me feel uncomfortable the consultation rooms have no windows and at lunch theres only enough seats in the staff room for existing employees so i'm always turfed out at lunch to wander around crying dreading going back with the general happening of calling my mum asking for her to console me with the guilt of knowing she is also having to deal with the death of my Grandma, the people arent too friendly and the hours of work are just horrifically strange, and the dentists are overly demanding considering i've only ever worked with one dentist and so i'm used to how he worked, they expect me to just know and I feel so much pressure to just know. I've been proactive about how I feel and applied to college however I feel that its just too late for me to do anything substantial, for example most courses take 3+ years and by that time i'd be 23+\- THEN i'd have to go through the whole apprenticeship scheme again to get to a decent position and by that time i'd ideally want my own life like any normal person instead of still depending on my mum and dad because I dont earn enough, that being said, ive applied for other jobs/apprenticeships in the hope of getting an interview so I can move forward that way which is more ideal because i've got a car and phone to pay for which I wouldnt dream of putting on my parents, sure I could get rid of my car and pay off my phone but i'm not sure thats any way to live. It seems like im answering my own questions but i'm just going round in circles and im not sure how much more I can take, I already have severe anxiety and depression and I feel as if this is pushing me over the edge bit by bit. I really need an opinion that isn't my mum and dads, its driving me up the wall

I'd appreciate any comments, thank you!

ok first of all don't let age stress you out. You shouldnt be in a rush to get anywhere by a certain point in life. I made that mistake. I wanted to be a fully qualified teacher by age 21 and I should have been. But uni was tough and then I got a job instead of doing my pgde, then i got rejected from my pdge and put off applying again due to fear. long story short, I spent most of my time in my graduate role at a job I hated (boss didnt like me) no progression and always feeling like a failure for not having became a teacher.
I'm now 25 and just a few months ago quite my graduate role which i was in for almost 4 years to become a classroom assistant in order to gain more experience and reapply for the pgde.
the point is all those years I just spend beating myself up, feeling like a failure, telling myself everyone had it sorted and was so many steps ahead of me.
there are always people out there who seem to land lucky. But me not becoming a teacher by 21 doesn't mean i'm a failure. I needed to get out of that mindset.
Now i'm working in a school and have decided that actually I kinda idealised teaching. and i'm at a point where I'm letting go of what was my "dream" it's hard to accept that something isnt for you after spending over a decade of your life thinking its your calling but sometimes things have to be done to move on. There's no point clutching to this dream and constantly feeling miserable that i'll never achieve it. Its not wrong or anything to be ashamed of to say "yeah i grew up thinking i would be that but i changed my mind, i tried it and it wasnt for me". So the same goes to you.
It's ok to take a step back and focus on your health, or go off to collage and take a little longer to get qualified than you had hoped. What your aiming for is an ideal version of you and why put that pressure on yourself coz like I say I made that mistake and all it does is make YOU miserable. I always though others judged me and saw me as a failure too but of course they didn't, we are our own harsh critics.

Now i'm 25 and considering to be a trainee dental nurse. It's not how I saw my life but does that make me a failure? no.

Do you like the job itself and it's just this new practice you are struggling to fit into, or do you have doubts you are in the right profession.

Hi,I’m having a similar problem and feel really upset. I’m 16 and finished school in June and I decided I wanted to do an apprenticeship in dental nursing (wrong decision) so I created my cv and enquirer to so many dentists hoping to find one which I eventually did which I was so happy about, I started in September, by the end of my first day I hated it but thought I had to see what the day after would be like and it was the same- I don’t like the dentist I’m shadowing (with another dental nurse-who I do like) which makes it worse the hours are too long for my age and I have made such a big mistake choosing to do an apprenticeship over a full time course at college. I want to change but idk what to say to the dental practice as they all think I really like it!?! Help me please!! Lucy xx