Is this lawyer in the right? Should I pay him?

I was married for a short period of time while I was deployed overseas. When I came back my wife left me for another man. She told me that she didn't want my money, but that quickly changed. We couldn't reach an agreement individually and she got a lawyer. I met with her lawyer and she was requesting 3300 dollars to pay for some stuff while I was gone. I thought that since she left me, I should not have to pay anything. To be on the safe side I talked to a lawyer and he said that what she was doing was unjust and that we should fight. I told him I just wanted to walk away without having to pay her anything. I figure lawyer fees would be cheaper than the 3300 she was requesting. After a long period of time and my lawyer finally collecting all information. He told me it was in my best interest to settle with her and giver her the 3300 dollars. I was upset about this, but I guess he's the lawyer and would know best. His retainer was 1800 and now he is charging me another 1700!