Hi TRR and a warm welcome to the site

You're definitely in the right place to process a painful, sudden, complicated ending of a relationship; that is really familiar to many members here.
It's good that you're able to reflect on what happened -- how there were red flags even at the beginning that for whatever reasons you missed, how things seemed so good until they were so bad, how you realized that it wasn't a healthy relationship and made a choice to leave the unhealthiness.
The main thought hitting me right now is that as hurtful as your relationship with C was, you are giving your boys a gift by showing them that it isn't healthy to let yourself experience a controlling, cold, blaming, paranoid partner.
How are your kids doing with the changes? Are they aware enough to be asking questions about what happened? I think you have a real strength in being able to say here that you recognize you fell into some old bad habits, and need to make some changes in your life. That too can be a gift to give your boys, that you can model owning your choices and committing to a new path forward.
Lots of members here (myself included) are making it through with the help of counseling. Is that something you might be up for trying?
Keep us posted on how the past few weeks have gone, especially the paycheck issue.
kells76