could anybody help me make sure i’m not fucking myself over?

i need to find someone who can listen to my complex situation leading up to me getting terminated effective immediately, and help advise me on whether or not i should sign the severance agreement my former employer wants me to sign. i was fired tuesday, got the letter today via email (backdated for tuesday), and have until end of day this coming wednesday to sign or not. could anyone help? i can’t afford a lawyer so i’m turning to reddit. edit to add: i am in colorado