It sounds like your biking has been affected too much in various ways by your DH. You're using his old bike, trying to ride at his speeds and on his routes, etc. Totally without his meaning to, his pervasiveness has sort of appropriated your joy in biking. To be fair, you have of course gone along with this trend, it's not all his doing.
If i were you I would get my own bike and go on enjoyable solo rides at first. Something with no pressure, something just fun for YOU. Be good to yourself!

My DH proposed fixing his old bike up for me when he got his new bike. I would have absolutely none of it! I made it clear I wanted nothing to do with a hand-me-down bike. He accepted that graciously, and then he helped me immensely in deciding what bike I should get.
While he waits now for his new bike, he fixed his old bike up for errands, with basket, upright bars, etc...and he likes riding it much better now too. It's also handy for when we have company staying with us.