That's actually a pretty large amount of talking!
Well, seeing as how you asked us anonymous strangers on a web site, I'll tell you some things that I think.
What jumped out at me was "Our sex life is not that great because we want different things." IMHO, it is just fine for two people in a relationship to have some differences of opinion as to what is fun in bed as long as they don't really give a rats ass if they ever actually get them because what is going on is effing fabulous.
Does not sound like the case for you. Sounds like the DL issue and probably other things get in the way of a positive sexual relationship. I speculate that you both know the other partner wants things that are not interesting for you, and that romance and sex get all complicated, to the point of not working, because of it. Not good.
I've been married to the same woman for decades. People ask us occasionally how come were still together when everyone else is divorced and remarried at least twice over. We usually mumble something about being great friends and having common interests (both true), but the straight answer is : Fantastic sex. Its not the "only" thing, of course, but when times are challenging, it is very helpful to look at your partner and honestly think "Well, he/she may be being a complete ____ at the moment, but he/she is the best lover I'm ever going to find!"
You can figure out what I think. What you do is your own choice.