I am glad you are pinpointing how you feel about the relationship. And I am glad that the course is highlighting for you even further the dysfunction and how he triggers you.

I think you are hitting a place in your relationship now where you see you have tried just about every avenue, and it still doesn't work.

If you do leave, at least you can say that you tried your very best to make it work, and you can leave without any regrets about not having tried hard enough.

And, IF you happen to be scared of being alone again (and I am not saying you are - hypothetically), I will tell you something:

I was afraid of it myself at my age. BUT, over time (and that's just in 2 months), I have learned and gained so much from being alone. I am more comfortable with it now, my life is far more peaceful as a result, I am regaining myself again, and I am feeling far better about myself and about life again. I am enjoying my own company and I enjoy the solitude and peace that comes with it.

So, if you find yourself being scared to leave out of fear of being alone, don't let fear hold you back... it's a falsehood. We can stand on our own two feet without a partner.