legally you’ll only be able to reclaim what you can prove you purchased.
start w/ asking him for your stuff back.
If you’ve already done that then send him a certified letter requesting your stuff back.
state in the letter the specific items you expect to have returned to you. Make note of which items you have receipts for in the letter. Give him a specific time period to return those items to you before you take legal action to be reimbursed for them. (word your request so it’s obvious that you are prepared to take legal action if your undamaged property is not returned to you in a timely manner.) Make sure you keep a copy of the letter.
If he refuses then you take him to small claims court w/ proof of what is yours and request that the items be returned or that you be reimbursed for their replacement value.
if he wants to be rid of you, then the threat of court should scare him into giving you your stuff back.
If he wants to play w/ you some more then he’ll force you to drag it out in court. So I suggest the stuff you want had better be worth the inconvenience & court costs of fighting him.
Honestly, if they aren’t HIGHLY personal/sentimental items just forget about it. You can get new, let him have the used crap.
If you are hell bent for high water to get stuff then take him to small claims court.