Lawyer Acting Erratic And Weird After I Paid Him

I'll try to be as vague as possible. Basically, I'm an artist who was screwed over by a major label. They owe me a loooot of money, most likely 6+ figures. I paid my lawyer for his time helping me with this case + to make a subpoena against this company for a statement of how much they've made off my music. I made that payment a few months ago. Ever since then, he's been extremely pessimistic about my chances of settling with them out of court (after seeming totally confident before), arguing with me about how to proceed and now he's asking for more money? To me it seems like he spent the money I sent him and is desperately trying to get more from me.. Should I just fire him and get someone else? Or try to talk some sense into him? I'm disappointed because he keeps asking for more money and hasn't said anything about getting the statement. This is a big deal for me and he doesn't seem to care anymore.