want a divorce

What is the name of your state? ms
Left my wife in last part of 1999. In 2000 she served me with papers for Separate Maintenance and Other Relief. Got a lawyer went to court and she agreed to divorce and 20% of pay. When she rec'd papers, she said her lawyer lied and she would not agree to divorce. I fired that lawyer. I have two sons, 18 and working and out of school, and 16 and working part time and going to school sometimes and failing. I have been paying the 20% to her since 2000 and she says she will not give me a divorce. BUT I REALLY WANT ONE!!!!! Do I just hire another lawyer and take my chances or can I fill out my own divorce papers, file them, serve her with papers and go before the judge and let him decide? Don't really have hundreds or thousands to spend hiring lawyers since I already went this route and just want a divorce. Could you please give me your best advice.
Thank you.

Also, it states in papers now that the 20% goes to house payment and utility bills and any thing left over goes to her. I have the option to pay myself and let her pay. I have to send here copies of my paychecks since I don't make the same every week. Was wondering what to do about the house since I really am paying for it. She says that the reason she won't give me divorce is because I owe her and the kids and the 20% is just not enough. She wants 20% plus make house payment and utility bills. She works and both sons have cars now and she doesn't because she does not have a license and never has had one in her 50 yrs of living.