Don't worry too much about your "negative energy" - it is NORMAL. Just keep it in perspective, feel your feelings and let them wear themselves out. If you repress any of it, it will just resurface later.
Even if you go with mediation, you should meet with a L at least once to become informed as to what your rights are. Your local women's center might have low-cost or free services, as well as Family Matters at the court. Do you have a case worker at the hospital? They might be able to help, too.
Go into ANY discussion with him with documentation. I believe that the first order of business is financial affidavits from both parties: what you earn, what you have, what debt you carry. You should be able to find the forms online, too.
It is an unknown, and it is scary, and it sucks. But you have a chance to get in the driver's seat with this part of it - keep as detached as you have been while you go through this business, because that's what this is - business.
BH, you sound so good for all that you are doing and handling... ((((BH))))