Really struggling to adjust to having a full time job

Hi everyone,this is my first time posting on TSR. Long story short, I have always been quite an ambitious person, left my country to study in the UK with not much support, graduated from a RG Uni with a very high first in Accounting and Finance.Finding a job was not a problem at all. I am currently on a training contract with a major accountancy firm. And I find it extremely difficult to adjust to this new life.Objectively, my job is not too bad. My colleagues are mostly nice, I get to leave at a reasonable time (typically I am out by 6pm) and so far I received very positive feedback. My colleagues are very stressed though and some of the managers I work with are chaotic and very badly organized which leaves the stress on me. My team has unrealistic targets to meet and even though I keep telling myself it is not my problem, I still end up caring. I can do my actual ob without any major struggles and don't find it particularly challenging (sometimes the vast amount of work can feel overwhelming though).Studying for ACA can be challenging and very time-consuming but I have passed my first three exams without real problems.My biggest issue, however, is the way I handle stress. For some reason that I really struggle to pin down, I am stressed pretty much 24/7. I think about my job nearly all the time. I cannot sleep at night (sometimes I get as little as 1-2 hours of sleep), and if I do I often wake up to discover I had some dream about work that woke me up.I cry a lot at home and generally feel quite miserable. I also started to put on weight without really eating more food than normal (even less as I started to count calories the moment I saw the scale go up) which makes me think might be stress/ lack of sleep related as well.After three months of life like this, I am exhausted, depressed, very miserable and I constantly think of leaving my job. I can't really do this though as I would really like to get my ACA. Despite being quite ambitious all my life, after I get my ACA I would be very content to find some easy-ish job that doesn't have to be super well paid in a charity or a school or other environment that is less overwhelming than my current job. For now, however, I feel pretty much stuck which makes it even more difficult to relax. Bad as it sounds, I would actually like to learn how to care less about the job. I am there pretty much for the qualification and experience and not for the promotions so it doesn't make any logical sense for me to be overly stressed - I will leave the moment I get my title. I have to survive the next two and a half years though, and for now it seems daunting to say the least. I am not saying that I want to start slacking at work, I just want to get some balance and restore my well-being.Do any of you have any tips on what should I do? Can you share if you had similar problems?Thanks