Op, your updates are horrific.
If he is out all day and not bringing in money then what is he doing? He is either earning money and not giving it to you, or lying around doing nothing all day. Either way, he is not a keeper.
Please get some proper advice, and I did recommend Life Insurance before, but if you do this, then please make sure that it goes into trust for your DC, and appoint people that you can really trust as the trustees. That way, they could release money for the DC's benefit and ensure that he can't just blow it all. But be aware, that he could challenge that though if he has been dependent on you
I hope you can take some strength from the various responses on here, and do something about your situation. He is a leech, he is draining you, and I rarely say LTB, but I really can't see what he is bringing to your life.
If you can get him to leave, and he won't leave you alone, then report him to the police for harassment. He probably won't bother you at all if he realises you are serious and won't give in.