If material facts were not disclosed, concealed or have changed since mediation, you can move to set aside your mediated settlement agreement. However, courts don't take this lightly --revoking consent to an irrevocable agreement that you presumably had legal advice while signing, is difficult. Nonetheless, if you feel that there you have grounds to revoke consent- fraud, illegality, impossibility, etc., then consult your lawyer and request that you revoke consent due to the recent CPS...
You should contact Legal Aid of Northwest Texas. They have a Collin County branch. They help folks who don't have the resources to get a divorce. Also, I highly recommend that you get a safety plan and go to a shelter for domestic violence at least for some resources. The Family Place, Genesis Women's Shelter are two great resources. You need to protect yourself and your child from the cycle of violence.
If there are no witnesses to the domestic violence episode it is difficult for the Court to proceed in prosecution. I recommend consulting with a criminal attorney to address the implications of family violence assault--especially if you have children.
Depending on what the affidavit says about the risks to your son's safety and welfare, you can attempt to dissolve the TRO and have a hearing on why dad should not have custody Dad's absence coupled with lack of child support illustrate his lack of involvement. You need to retain counsel to represent you at the Temporary Restraining Order and show evidence of exactly how you are not a risk to your son. As for the lack of communication, as soon as this goes before a judge, dad's blocking...
Every courthouse has a law library. The local ones in Collin and Dallas have prove-up questions to finalize your divorce, and some counties have pro se (unrepresented) dockets where the judge will approve of your decree. You should make a trip to the courthouse if you are not going to hire a lawyer and ask the clerks where the law library is and inquire what the local procedures are for an unrepresented client in that district.
To ensure that you have the true grounds for divorce, you must plead them with a counterclaim stating adultery as the fault in the breakup. Ask yourself what you hope to accomplish by pleading adultery and how this can help your case, strategy, etc.
If you suspect and have tangible evidence of family violence, contact a family attorney to modify your ex's access to be supervised. If you have notice or knowledge of dad's propensity for violence and do not act to protect your two-year old, this could result in a CPS referral. However, prior to modification, do your homework and find out whether there is a protective order, police intervention between girlfriend and your ex, or whether there are any other convictions for family violence by dad.
First, when you are dividing any asset in divorce, you need to consider whether you value cash, assets, and how to achieve that goal. In trying to keep the house, if it is truly your only asset, you need to consider whether you have other separate property or capital to buy your husband out of his share of the home. I recommend seeking counsel to creatively consider your options.
Modifications can be made for material and substantial change. Behavioral issues may be construed as such a substantial change. You need to produce measurable data, counselor's notes, testimony and information to illustrate that mom is harming your child's emotional welfare.