My suggestion to you is to let go. Sooner or later, it's gonna break, and the sooner, the better. I know it doesn't sound very feasible to you, but you can make it on your own. Looks like your partner is not striving to make this work. Let go and start afresh. It'll take you a while but you'll move on
Also, you deserve someone who wants to be with you and loves you. Never settle for anything less. You deserve better 🙂
Have you tried telling him about how you have been feeling.
And this is not how you save a relationship it has to be 2 sided efforts.