EDIT: SORRY the title should be HOW to continue the sexual adventure!

So, my significant other and myself met and began a sexual adventure that lasted 15 years. Pretty wild. She had incredible experience, and we would do almost everything, often inspired by porn movies.

And then... life changes. The adventure has stopped for her, and she seems to just want to turn into a cantankerous old woman. It's still a strong relationship otherwise. We've been together a long time.

Her response is to help me masturbate and get pleasure, but this is awful. Just awful. There's no turn on if the other person isn't really into it. I do not blame her. It's just time-of-life stuff.

For me, well, it's the old cliche. I still have needs. My sexual adventure must continue. I'm still growing sexually.

I've been experimenting with online affairs here on Reddit, but it's one heartbreak after another. They start well, and get intense, then something happens. Always. Back to square one.

So, I throw myself on the mercy of the court. Please don't be mean. But what should I do?