I have found that a lot of people think that everybody does no work and gets better results than them, when really, these people do a lot of wor without really telling any one.
If you are having trouble getting organised, there are things you can do, like writing notes etc. I'm sure reading up on how to keep organised would help.
Similarly, perhaps you haven't quite learnt how to work yet. I mean no offence, uni is totally different to school, I did no work at school and managed to get by, so never really learned the skills needs to get down to work. Untill this year (second) to me revision was glimsping over what I generously called notes, unsurprsingly my results could have been better.
Now I take more detailed notes, I read up on stuff outside of lectures, and when revising I write even more notes, everyone has a different method of working, perhaps you just haven't found yours yet.
Talk to your tutor about this, maybe they can recommend some acadmeic skills books. It's too soon to give up, when there are plenty of things to try.
If you really want to eliminate dyslexia as a possibility, write to your lea about getting tested.