Help.

So, i am a supp main. Last season i was silver 3, however i was downranked after elo-reset to b4. Ive made my way out of b4 to b2, where im kindo stuck in. Now, the problem is, that its slowly very frustrating for me. I even dont play supp any more in ranked, because there is always that one guy(we know him all) who goes 0 10 against a yasuo-zed-whatever. So i just want you guys to ask, if there is a method or hint that i dont know, which can help me in my situation, without changing my main role, because i really enjoy to play supp. People always say, learn from every game, but that is kinda heavy, when every game is so... complicated in terms i mentioned before. Im really interested in getting better, and its not the standart "my team is so bad, gg". I believe there is a thing I do wrong. Last season i got out of bronce with abusing morgana mid, but that isnt working anymore(seems to me, dont know why) So if u got any hints or questions to my gamestile feel free to leave an answer. :)