Divorce Support Forums: First post/backstory/vent etc

Hello all. I apologize in advance for what will be a very long post. I just need to vent/ask for advice. This whole thing is a bit overwhelming.

My stbx and I were married in 1995 and we have two children (11 and 9). I moved from the marital home on 11/1/04. Since that time we have split physical custody of the two children with one parent having them one week and the other having them the next. There has been no child support going either direction. We had a verbal agreement that we'd both pay half their expenses, but the reality is that I have paid significantly more due to him being unemployed the majority of the time.

During the marriage there was a lot of poor behavior on both of our parts. I am not an innocent angel. I was a sahm who did not take care of the home very well. I did take care of the kids, but the cleanliness level was bad. He did nothing around the house nor did he maintain a steady job. Our bills were barely being paid, utilities shut off multiple times etc. He also had an affair and has a child from that affair. We split up because of that affair in 2000, but got back together and remained together until 2004. From 2000-2004, I misbehaved online in the sense that I had a few inappropriate emotional relationships. I never had a physical affair nor did I even talk with these people on the phone. All online.

Since 2004 I have maintained the same employment, the same residence, and have increased my income by more than $6,000 a year. I currently have 401k investments worth more than $7,000, maintain medical insurance on both children, and contribute to a 529 plan (college saving) for both kids. I currently live with a man who moved in with me 5 months after I left my stbx. He is caucasian (as am I), has no criminal history, does not drink, and does not do drugs. The stbx has never in three years raised a concern about him being around our children on a daily basis. My children do come home from school to an empty house in a latchkey type situation. In addition, I drove for 3 years on a suspended licence, but I do currently have a valid driver's license and insurance.

Since 2004 my stbx has been through multiple jobs and maintains no steady income. To the best of my knowledge he is not currently employed. I am unsure how he pays his bills other than it appears others help him. He does not do drugs nor drink to excess as far as I know. He dates a woman but does not currently live with her. He pays child support for his other child, but was arrested last year for being in arrears (he claims to no longer be in arrears, which is possible)

After attempting to come to agreements with my stbx so we could file for a dissolutionment, it became obvious there were a few sticking issues that were not going to allow it. I finally filed for divorce and asked for residential parent with visitation remaining as it has been for the last 3 years. I asked for residential parent because my stbx wants to move the children to a different school district and I would like to keep them in the district they currently attend and have attended since kindergarten. To protect myself, my lawyer recommended I file for child support even though I didn't really care to.

My stbx called me when he was served with the temporary order and was very upset. I offered to give the child support right back to him each week, but have since decided to keep it and put it in the kid's college accounts instead. He claims I have made a big mistake and will lose custody of my children. He claims that he has hired a very expensive attorney (on his sister's dime) and will fight me tooth and nail until I run out of money.
I guess my concerns at this point, aside from the just needing to vent my nerves, are just how much he can drag things out, and how likely it would be for me to lose? I do understand that the likelihood will be that I end up paying child support in the end since my income is higher than his, though I don't find that fair considering he chooses to be unemployed and I pay for more than 50% of their care because of my higher income, but I digress.
I can afford my lawyer for a bit, and he'll work with me on a payment plan even after I can't straight afford him, but I really wasn't looking for a tens of thousands of dollars divorce. Feel free to ask any questions I forgot to answer.