I'm at a loss

I really don't know what to do, am I doing something wrong?

I just unlocked comp, I'm just starting it. I haven't won a single match out of 15-20, is my luck really that bad or is it me?

I've looked up all the tips for competitive, I pick chars that go well with my team, I pick support a lot because nobody else does and I make sure it unlocks team abilities for ppl. I'm decent, not bad, I just completed a round with 20 assists and 10 kills as cloak and dagger, I'm focusing on healing/blinding and staying back but my teamkeeps trickling in 1 at a time and dying. They aren't picking anything that works together and they aren't playing the objective. I don't know what to do... I try to hover near the objective and wait for my team but they show up alone and no amount of healing will save them.

Somehow my opponents are always working together with great composition like pros and we seem like bots.

Idk, what did you guys do? How did you get through bronze? Is there a reason I'm getting such awful teams and my opponents are so fluid together? Does something carry over from quick match/casual? I always seem to do really well there and thought that could get me paired with bots in competitive to balance the teams somehow, idk. I just need help figuring this out.