How to protect myself and my spouse from retaliatory action once I sign my severance package.

Greetings,

I was recently laid off from a local Parks and Recreation who also employ my husband as an instructor, site supervisor and he also volunteers
2 nights a week to run open gyms for the local kids. I was laid off last Friday, 10/30, and told that I was eligible for a severance package IF I signed an agreement that stated I would not EVER say anything publicly negative about my previous company or anyone who works there and not speak to any confidential information I may be privy to. When I did not have it signed by Tuesday, my previous employer pressured me to sign as I was "placing the agreement in danger" and that everyone's job was in jeopardy, including my husband's. I was then told I had until Friday to sign, and my husband received a call the same day informing him that his access to the building he hosts the open gym in has been revoked while my previous employee decides if he can be given access.
I did consult an attorney about the harassment I experienced during my employment, my knowledge of unethical behavior and about the agreement, (he advised me to go to my previous employer's board but they will not meet for another 2 weeks) but our meeting was prior to my husband's access being "reviewed". I find it interesting, and threatening to have been told that they will tell him Friday whether or not he can have access, which just happens to be the same day they are demanding my severance agreement be signed.

I am willing to sign the agreement if there is a way to stipulate that there is no retaliatory action taken against my husband. Because of the way his salary works (he is paid a percentage of the enrollment fees) they can't say there are no funds to pay him with. Is there a way to add a clause that says he cannot be fired without cause? He has an excellent record, and I am trying to protect that income. He has worked there for 6 years, and runs over 8 programs not counting the open gym. I was not let go due to economic reasons, but at this point I need to protect my family, which means we need the income from my husband's coaching. I also want to know if I can add a statement saying that I will not say anything negative relating to events prior to my layoff. The way the agreement is worded, if I enroll my child in a program, and don't like it, I can't even complain.

I look forward to hearing from you,