I have been suffering from Mental problems would you please give me a piece of advie

I am a second year university student I used to be very dutiful to my subjects homeworks or whatever I am still the same but there is personality disorder or mental problem to which i could not heal or find an appropriate treatment when i do a very simple homework which can be easily finished in 1 hour i just do not get relaxed until i pay my hours or even days over it and besides no matter what i produce i am never and ever satisfied with it i feel like i omitted some information accidently i gave misleading irrelrvant totally crap information i started to think about everything i have now became a person who is stuck with every detail
Because i stick with everydetail everything i can not see the big picture someone says i am suffering from being a perfectionist and i should see a doctor
I am now in a position that i do not get any pleasure from my life because my mind is always occupied with thinking about details
Last semester our teacher gave us this homework that we were supposed to write 20 pages semester-end homeworks and you have no idea how painfully that writing process went for me I cried every day for not being able to write something I could not just write anything for months not a single word and then I started little by little and tried to produce something the totality of pages could not reach to 20 it remained limited to 5 during those three months i came to realize something that i cant handle such stuff but i thought i could so basically that incident demolished my confidence drastically and now i recently started to think about writing a dissertation i have started to think like 'how am i going to write a thesis when i cant even do a 20 pages homework?' How can you survive from that 3 month thesis process when you cant even survive and cry to your parents everyday because the 20 pages assignment didnt go well as you anticipated it? I feel like i will be crying more and will be doing more damage to myself in the last year of my education because i dont like writing ive always disliked writing and whenever i have to sit down and write something i want every line to be perfect that is why i Cant Ever make a REAL PROGRESS i think a lot about a lot of stuff ' this word does not fit in here' 'this grammatical structure is so poor' ' even a secondary school student can write your paper' ' what a garbage youve produced' 'ideas comprimes no novelty' 'your paper seems like nonsense and smells garbage' i always think that way and this feeling and all these thoughts are eating me alive people around me see its early to think about such stuff because i have 2 years
But if i dont know how to write a thesis i cant graduate and thus i wanna be able to produce not something but something perfect and that is my problem
I cry over it every day what i i fail and cannot produce a good work? My classmates do not even read i doubt whether they know the meaning of a thesis or article they do not even know what an article looks like how to quote how to cite how to refer. They all know just popular novels. But they are so calm and relaxed about this they do not seem to care at all. But for me things are not the same i do desperately think about this matter everyday i have poor writing skills and no matter how i try they are not improving i cant make them advanced i am psychologically distrubted. My mental has been destroyed irreversibly i do not think i have confidence now i cant truly be content with my life no matter what i do i cant get over this problem please help me