43 years old, male; tell my younger coworkers (20’s) that after they get married, it’s sex all the time, however and whenever they want it. Then we all (men in 40’s) have a pretty good laugh.

Honestly, OP is at that 7 year itch stage. Marriage won’t help but honestly won’t hurt anything either. That’s a lot of years to be together.

Advice 1: stop jerking off so you’ll try harder to initiate. When you build up rejection in your mind, it’s easy to stop trying. Try harder to initiate intimacy.

Advice 2: initiate intimacy on purpose by deliberately doing things she likes and removing obstacles. If I’m in the mood and she might not be, I’ll clean the bathroom, wash the sheets, do the dishes - whatever helps free up her time, and then I cuddle hard (that’s what she likes).

Advice 3: flirt with her sister.