I'm going to be very honest with you - you've been making one bad emotional based decision after another - in turn creating a convoluted headache. Now you acknowledge he has depression issues and is looking into disability. That potentially just added a whole new layer of complexity. I will tell one thing with certainty - DO NOT TURN OFF UTILITIES OR CHANGE LOCKS OR PROHIBIT HIM FROM LIVING THERE WITHOUT A COURT ORDER OR AN ATTORNEY GIVING YOU THE GREEN LIGHT or you could end up in a world of hurt.
Every municipality has different tenant/landlord laws. That's why an attorney is your best approach when dealing with evictions when you don't know the full legal implications of your local laws.
You're asking advice to lessen your headache? Get him to agree to leave in 2 weeks (or whatever is the quickest he'll go) instead of evicting him and cut your losses. He doesn't want an eviction on his credit - get that message through to him. This is your lowest cost, "stop the bleeding now and end the headache" option. Forget about what he owes you, don't get lost in the trees. Evicting could cost a lot more time and money. And you'll end up spending more if you hire an attorney. As long as this guy is in your property you will be dealing with issues daily. Is it worth it?
Yep land lording probably isn't for you. But you can be a hands off investor. Get yourself a property management company and just collect your checks - whether you keep this place or 1031 into something new is a personal big financial picture decision. You're a sucker for hard luck cases and let me tell you, from my own experience - no good deed goes unpunished.