Ex step mother in law...HELP

Ongoing need for advice on this...

Was in a relationship for about 5years. My ex and son bonded in that time..my ex is not my sons biological father. The relationship was toxic and ended toxic. I did attempt to keep he and my son “together” because my son loves him but my ex crossed some boundaries and I now feel I need to seriously take time to heal since I never got the chance due to trying to keep connections between my son and ex.

Now that I’ve greatly limited/ended communications, my ex AND his mother text me every so often about being able to see or speak to my son. I don’t feel ready for that at all and want a lot of time to pass so we can get used to our new normal. But I’m struggling with some guilt.

Am I shitty for standing firm on space and ending ties or am I damaging my son and should allow contact?