His responses to you are just abuse, and I think your years together have made your pain 'familiar'...
That's why NC is wise, you move away from that & get to know & love yourself. You know you don't deserve the verbal and emotional beatings he's dishing out!
Filing for D is not "pulling the plug".
It is a beginning of a process that takes time - sometimes too much time - before it is finalized.
Plenty of time for him to initiate changes, meanwhile, you're heading in the right, healing direction whether he steps up to the plate or not.
Do it to protect yourself, see it as a process, not a cliff you are stepping off of - that's too dramatic (& is not the case anyway). Don't let the fear of what is not there keep you from taking steps to protect yourself.
I don't care how he "looks" on the outside, he's mean and rotten within.
Too, taking viagra while on bp meds is like masturbating against a passing freight train -
it's not going to end well for him.
Distance yourself from the damage. File. Begin the process.