Taking care of you and your kids isn't tough love, it is called self preservation. You have two kids to think to think about that require food, clothing, shelter. Good that you won't let him stay with your parents, I'm sure they appreciate your consideration.
Work on getting your life sorted and together. Giving money, etc.. will only encourage him to keep on contacting you etc. as a viable source of drug money. Active addiction doesn't care about people - only about getting high.
Let go of him and the drug drama.
Take it all one day at a time. And read here on the boards. A lot of "posted" messages up at the top with excellent guidance, advice and resources.