You did the right thing C

I like middlepaths train of thought

Its hard to say no when someone reaches out, especially someone who used to be an important fixture in our lives, but dammit sis its time we learn to say yes to ourselves!
Don't feel bad, you did nothing wrong. Your plate is filled, 2 sons, each with a broken arm (among other stuff) and now your ex wants you to play nursemaid to him and provide shelter while he drys up? No. No. No. He's not your responsibility.
The other major things happening in your life, you didn't invite them to happen, and they are more than enough to contend with without consciously inviting extra issues to sleep on the couch for a while...
You did good hon

improved boundaries are a postive step