2 Year Old Not Sleeping Well

Yes, my son went through a period where he always needed to know where I was at all times. At 6, he still has days like that sometimes. I think during those times he is struggling with something and just needs reassurance that I am there to help him.
I would try moving your son's bed time up an hour - the old "sleep begets sleep." It might not work as one person said before, but it is worth a try. Still have him take a nap during the day. GIve it a chance to work, it might take a few days to get going.

Going through this myself. Don't worry...it will get better.
Try everything.
My son is 2 yrs old and he does take a nap during the day because he needs it......he's very active! And I mean very!
He skipped naps for about 2 weeks and that's it. I do try to tire him out in the a.m. before nap and in afternoon before sleep. He takes a 2 hr nap.
I do make sure for night time sleep that I change his diaper right before bed. and I mean right before. He was leaking out of his diaper and it was waking him up. I bought the next size up and tried all brands until I found one that was super absorbent. Target brand was decent but I've gone back to Kirkland brand from Costco.
The night light is key.
I do not believe in crying it out personally. That's just me.
Since I've made changes: bigger, more absorbent diapers, nightlight, a change RIGHT BEFORE bed...it helps. Most nights he will sleep through the night.
I also give him one last bottle of milk right before bed. It's also a soothing thing for him.
Sometimes he wakes from a bad dream...if it's the middle of the night I pick him up and hold and he falls back asleep in my arms then I can put him bk in the crib.
If it's close to morning like 5:30 or 6a.m. he will want a bottle of milk and will pass out in my arms. I put him back in crib for about an hr and a half.
If he has his own room, you should try putting him to bed in there. If you don't and he shares your bedroom, it could be that too but there's no easy answer for that one. Try everything! Good luck

Yup, going through this myself. Used to sleep through the night, but now wakes up between 12:30 and 2, we're too tired to deal with it so he sleeps in the bed with us. I think it's sleep regression that happens at this age.
Bedtime is 8:30, tried 8pm, tried 9pm, same thing happens. Didn't matter.

My daughter went through a phase where she didn't want to go to sleep on her own and would wake up a lot through out the night. What we ended up doing is as soon as she feel asleep we turned the brightest night light off and only had a dim one lit. That seemed to help with sleeping through the night. Also you might want to try taking nap-time out of the day. It might be a little rough on you all for a couple of days but by bedtime he should go to sleep with no issues and sleep through the night. That's what our daughter did. I hope this helps.