OP - yes, do the Freedom Course. And you might find it insightful to read "How-Gets-into-Her-Head - the Mind of the Intimate Male Abuser".
This makes clear that an abuser will target a woman whom he sees to be kind and ready to put others' needs before her own, then he sets about getting to know her extremely well, while withholding himself emotionally (though he might conceal he is doing this), and using his intimate knowledge of the woman to control, hurt and effectively brainwash her. So when you say you wonder if this is down to you - that's him talking.
Firstly, you must actually be incredibly strong to have survived years of this. That means you have the strength to disentangle yourself. It sounds like you've started to do that - you've started standing up for yourself more and more recently. That's terrific. That shows your instincts are intact. You may be out of practice at listening to yourself but you're getting back into the rhythm of doing so.
None of this is to do with his MH. Millions of people have MH conditions and still treat their loved ones kindly and respectfully. However, I think - with MH issues being increasingly brought out into the open - abusers are using them as an excuse for behaving abusively. That's because abusers instinctively weaponise everything against their partners and they never take responsibility for anything.
He will not accept that he is abusive (abusers very rarely do) so don't expect him to admit to it.
You've given him 10 years. You've given him every chance and more to behave himself and act like a reasonable and responsible partner. It sounds like you're done now. That's great.
Do you have people you can reach out to IRL for support? In any case, keep posting here if it helps. And be gentle with yourself. Disentangling yourself from anyone you've been with for 10 years would be difficult and painful. Get as much support as you can and look after yourself during this process.