Advice for making one's heart behave? Fresh out, I'm afraid.

All I can think of is practical stuff. Make/maintain as strong a support system as you can. Get a counsellor / therapist / whatever if your medical covers it, not to fix anything but so that you can vent safely and freely without guilt, when you need to. Organise your finances so that if you need to take complete control it can happen seamlessly and without financial penalties. Make sure everything is in both your names "jointly and severally". Don't put off doing things you enjoy together.

None of that is news to you, I know.