You say you don’t have feelings but then go on describing the feelings you have towards her.
A lot of times we’re just not awake to the kinds of emotions we’d like to be having. Bouncing around relationships looking for those feelings is going about it in entirely the wrong way. You think that the other person is responsible for evoking those feelings but really they come from you. It’s your brain that’s not working the way you want it to, not the other person.
One way to fix this is an open relationship. You stay with the one person you love but you let your sexuality express itself in the ways it won’t with that person. A great book on this topic is The Truth: An Uncomfortable Book About Relationships.
The Truth: An Uncomfortable Book About Relationships: Neil Strauss: 9781782110958: Amazon.com: Books
If you’re not familiar with Neil Strauss, he wrote a famous book on pick-up artistry called The Game. This book picks up where The Game left off and describes his journey to find satisfaction in love. It’s a phenomenal read.
Another great book is Mating in Captivity: Unlocking Erotic Intelligence
It’s about finding sexual fulfillment in situations where switching partners isn’t possible, reasonable, or desirable.