worried about soon2b 3yrold son

my kid has me super worried. he'll be 3 next month. we are struggling with everything right now. potty training nap time bed time behavior education all of it. potty training - It's not going well he is having a hard time grasping the concept that needs to tell someone he needs to potty when he feels the urge. unless we ask him 50 times A-day he won't go and even when ask those 50 times if I go more than an hour without asking he'll use the bathroom on himself. And it's not a uh oh moment it's hidden by him he acts like nothing is wrong goes on playing and I don't realize it till I smell something or realize he hasn't said anything about potty in hours. It's been about 5-6 months. Starting to see some anxiety in him Especially in social situations if his brother is not there he does not wanna play with other children asks to go home several times . when brother is around he plays normally. Becomes very anxious at bedtime squirms like hes physically hurting. he seems to Rocks back-and-forth a lot when sitting on the couch he rocks a lot like hitting his head against the cushion... he has done this since he was small and some children do that just to fall asleep but we're realizing he does it a lot. He is the middle child so I can't imagine what hes going through in his mind especially watching his older brother not get in trouble or be corrected as much and we only have the older brother every other week so it's an adjustment for him and his brother ...and then baby sister not being disciplined because She's a baby and and in his mind probably looks like she's getting away with things he gets in trouble for. We understand that you have to explain things to them teach him right from wrong and a explain everything and why we do it but just fearful that there may be an underlying issue such as an attention deficit or sensory issues or mental health. any similar issues out there. And if you don't have anything constructive or nice to say keep your mouth shut and off of my post thanks