What do I do if someone keeps accessing my accounts & personal places and tries to hack into everything and I can't prove it is him?
If you can't prove it then it didn't happen.
depends on the accounts however if its social media accounts then blocking him changing your passwords including to emails and what ever else those accounts are linked too then establishing a two factor authorization on all the accounts that allow you to do so will pretty much ensure that unless he physically steals personal property to get into an account to break through this new barrier then you have a pretty obvious legal means of pursuit at that point. if its something more personal like bank accounts or investment accounts then simply talking to whoever those accounts are based with will give you a truck load of options to ensure you are the only one who can access those accounts. Also ensure if you have a wifi router that you change the password and stuff for it as well just in case he tries networking into you system.
Some level of uncertainity is necessary for not doing crazy things.