Can I sue my ex boyfriend for owing me money if I have a conversation of proof and copies of receipts?

A couple years ago I lent a tremendous amount of money to a boyfriend with the trusting knowledge that he was going to pay me back. We had this as an understanding but didn't document and sign papers because I had trust in him. We stopped talking for years but everytime I did get in contact with him I asked for my money and he always denied me. I recently found a lot of receipts from banks with large amounts of money and with his previous bank account number on one of them. I recently spoke to him and basically made him admit that he owes me a lot of money and printed out the whole conversation. I was wondering can I sue him with the proof of those receipts I found and from the proof of our conversation? I need some justice for him taking advantage of me for years.