Hi, S.! It is SOOOOO hard not to get your sleep. We have had sleep problems with our son frequently from the time he turned 3 and we put him in a twin bed. A book that REALLY helped me was "Sleepless In America: Getting Your Family the Sleep It Deserves" by Mary Sheedy Kurcinka. She goes into bedtimes routines, how to make sure your child is calm and ready to sleep before bed, etc. Her recommendations have been invaluable to us, and have given us so many great ideas, which have actually helped.
One of the things that helped us is putting a pillow and blanket on the floor next to our bed. We told him if he has a really hard time, he can come in, bringing his own blanket and baby and lying on the floor in our room. We encouraged him to come in quietly, that he didn't need to wake us up. Even if he woke us up, though, and needed help with his blanket, we ALL went back to sleep so much more quickly and slept better. We've had to do this with our son off and on the last year and a half, and we just start it up again when he goes through stages where he needs more help with his sleeping.
I would also be really careful to monitor what he is seeing on TV, limiting screen time, and checking that the books he is reading are not scary to a 2 year old. In my experience, there are SO many things that are shown to children, such as in children's books, that seem rather harmless but are actually quite disturbing to children. Check out the decorations in his bedroom in the dark and see if there is anything that causes shadows, or just looks scary in the dark.
Since your son is only 2 1/2, he does not have a lot in his arsenal yet to help him get back to sleep, and he really needs you at this point. He just may need extra time with you as well, and this way he is not in your bed, but he is close, and it may be just the thing he needs. This won't last forever! But I know this doesn't make it any easier for you right now. At least I hope it will help you sleep better! Please do check out Kurcinka's book--it was a lifesaver here in our house!
God bless!