Kicked Out of 6th Form

My story: I have had goodness-knows how many doctor's appointments since September for a reaccuring issue. After getting that solved, another popped up, one not so easily solved. I was referred to an ENT with a 25 week waiting list in December (shortest waiting list for ENTs near me).During this time, I had the first 2 weeks off of school due to the first issue and tried as best as I could to attend with the ENT problem, being late most days to just not attending. My mother has quite a temper and was growing more frustrated each day I had off to the point where she would come home from work to drive me to school to see the head of sixth form to talk about my attendance. It got to the point where I took a few days off school without telling my mum as she got quite angry whenever I said I couldn't go.This arrangement I worked out of going in late was eventually accepted, to my mum's displeasure. We got our GP to wrote a letter to school, generally saying that I am dizzy most of the time, which was accepted by the school.Now, after not going into school since the 8th of January (since the term started), my mum found out about my lack of attendance today and is, quite rightly, angry (understatement). My mum spoke with the head of sixth form, who has come out to say that they're kicking me out. My attendance is 55%. This is with no warning, letter or general notice with pre-warnings, just mentioning the need to 'consider over options' vaguely in a meeting back in October.To add to this, I had really only 1 close friend until October time since year 3. She comes out and texts me saying things about how she's her own person, and I've been holding her back, which is why her recent relationship failed. She quite bluntly said let's not be friends anymore (as if a friendship of 9-10 years could be forgotten in a night!) That destroyed me as I had not seen her in 2 weeks (the first 2 weeks of school) and a lot had happened during the summer holidays. She would not even ask me if I was okay on my first day back, instead asking through a friend, and is generally avoiding me. I have other friends, yes, but I cannot comfortably talk about any of this with them. It does not help that she is quite... annoyed? when she has to interact with me, which has been once in person since October. Ha ha. I have other, no where near as close, friends, mainly one who I can actually relax around but, generally speaking, I have no one to talk to when it comes to these kinds of things.Now I have a choice to make about what to do next. This is where I need help. My mum thinks I am merely crying wolf, underestimating the problem (dizziness, frequent moderate-severe headaches, tiredness (not just from lack of sleep), nearly fainting and vomitting more than a few times etc.). So now I have little choice, either get an apprenticeship, go to a college that has no appealing courses, or go live with my dad, which my mum is wanting me to do (he lives 4 hours away) as she doesn't want to deal with it, with me, anymore.I agree what I did was wrong but with a lack of support from my mum and my dad barely knowing what IS wrong, I did not see many other options. I have a meeting on Monday with the head of sixth form with my mum to talk about what to do next.Do not get me wrong: I've been attending my school for year 7-11, with 100% attendance in 7, 8, and 9 and over 90% in 10 and 11, not once having dealt with behavioural issues, got As and above in my GCSEs and am half way through year 12. I am not a problem student. Which is why I don't understand the lack of even a letter for frick sake. Furthermore, I have social anxiety, making it difficult to talk about anything personal to those outside my family. It also makes me anxious when it comes to going back after time off, not knowing how people will react. I do not speak to people about my emotions, having been brought up as such (with a mum who hides when she cries (which is rare), never have and find it awkward when I have to.To add to that, I just have no motivation to go in, saying