I suspect there are some deeper longterm relationship/communication issues going on here. If you really feel the relationship is breaking up and you deeply care about not wanting that to happen, then you need to get some professional counseling- either couple's counseling or just for yourself.
Don't get me wrong, people here are wonderful and always sympathetic and caring.... but bike forum advice is just not going to cut it. Perhaps he cares enough about the relationship to go with you. Learning better communication skills can make or break the situation here, and that takes counseling to learn properly. You would both learn a lot about yourselves AND each other- always a good thing.
A vacation together, flowers, spicing up your sex life, or a new hobby may help temporarily, but longterm solutions usually require deeper exploration of underlying causes. It takes two to make or break a relationship.