I may be about to leave the loveliest person in the world and I am devastated

[StrawberryMoonFace]

Namechanged and IDing details changed as I suspect both DP and some friends use MN.

I met DP fourteen years ago and we have been together for 13. We were 19 at the time, which strikes me as stupidly, impossibly young.

Over the years we have had some issues but got through. For a long time DP was very difficult to live with - timid, depressive, lazy, overweight and unhealthy and drinking too much. With great self resolve, DP has put all of that behind. I have also had issues with depression and I know I haven't been the easiest. When things were hard before, I waited for it to pass and counted my blessings. We have pets (no children yet), and a lovely house, and lovely friends.

DP worships me. And is genuinely the kindest and sweetest person I know. Frankly deserves much better than me. So this is breaking my heart.

The issue is, that after 13 years something has withered or fizzled. I feel this enormous resentment over all the things I have never done because of my commitment to this relationship. I have never really been a single adult. To put it crudely, I don't think I have slept with enough people. DP was only my 2nd proper sexual partner. I am no longer even sure that I am attracted to DP's gender. Or if I attracted enough to sustain me in a marriage for life.

I have spent most of the last week crying or feeling utterly despondent. I can't believe I am about to do something so awful to my best friend, my confidant. But I am also afraid of how much my resentment will grow if I stay.

For months now I have been trying to convince myself that I am not really a sexual person, or that if DP is 90% happy that can bolster my 40% to 60%, IYSWIM. But I don't think that's the case.

I thought we would grow old together.

DP keeps asking me what is wrong and is trying so hard to cheer me up and that just makes it worse.

Please be gentle.

I don't know what to do.

The fact that you say the sex has never been great for you - makes me think you are v likely with the wrong gender partner. I don't think there's any harm in being honest while being as kind as possible..

I think you tend to know when a relationship is at its natural end. And everything else is just dreading the fact that it's going to be pretty shit for a while and not particularly wanting to go through that. But eventually the scales tip so much that you have to.

I was with my first love through 6th form, a year's break as we went to different universities and thought we should try to make a go of independence. That didn't work so we had an LDR until we graduated and then another 5 years into adult life. I loved him very much, but we grew up and grew apart. Me, more than him, to be honest. He did nothing wrong, I just needed to spread my wings. Without him.

You can't stay with someone out of loyalty and fondness. You just can't and, honestly it's a bit rubbish for them as well. They need a chance to find someone who wants to be them for the right reasons.

It's not easy, but it is doable. Just have to grit your teeth and get on with it. And know that you're doing it for the right reasons.