Where Does All the Money Go?

I'm on disability now, as you may know. I'm making 70% of my former salary. I give about half of that to my soon-to-be ex-wife. My rent is not much. Medical expenses are a heavy drain. But that's about it. The rest of my expenses are fairly small. And yet, the money always seems to disappear without my even being in control of it.

I have yet to figure out a system that works. Or, should I say, I have never found a way to follow a system to keep track. It's been one of the banes of my existence for my entire life. Why can't I do this? I just have this mental block that steps between me and my need to impose some order on my life.

Thought, suggestions, and donations welcome.