Hi Ro...All you can do it detach, concentrate on you, do anything that makes you feel good. (in a healthy way) for me I quit smoking, started dieting and exercising, ((I've lost 50 pounds) and fixing up my house (it was nice not to think H wouldn't like something I bought for the house!)
When I was at my worst therapy helped, reading here helped, venting here helped. Having a plan whether that plan was simply "I won't text him today"
When you first start GAL activities you feel disconnected. I remember being out to dinner, or at someone's house and feeling detached wishing I'd stayed home all I thought about was him and feeling sad. And slowly you start refilling that hole that was left when by them with love for yourself.
It may help to know that I was there (where you say your H was) and it all came crashing down and I had my own time of extreme unhappiness. However if I had chose to continue to self medicate myself with partying and male attention then I may never have taken a look at those feelings. Plus pride is huge is was really really hard for me to admit that I'd made a mistake and it may be even harder for men.
All you can do is take good care of you. bubble baths, walks, cozy pjs, nice food, anything to make you feel cared for. You need it right now!
