I very rarely post in this forum but reading your posts I feel compelled to reassure you that leaving is the absolute, only, thing you should do here.
I married my ex when I was 31 and within 18 months we split, when I was 33.
We had VERY similar sounding issues: no sex, no communication, him never complimenting me or even giving me a second glance in sexy underwear/bikinis.
He was completely focused on work - he'd be there until 8 or 9 at night and then work over the weekend too - but was always tired, miserable and grumpy at home with me. I tried so hard over the years to tell him how neglected and rejected I felt but nothing ever changed (I also put lots of effort into trying to help him feel happier in his life too!!)
At the same time, superficially, we got on well. We were both successful professionals living in London and enjoyed the same restaurants and holidays. Our families got on well, we owned a lovely flat and we never argued. But we were basically flatmates who shared a bed and for a long time before it finally ended there was no emotional or sexual intimacy, hardly any fun and laughter and an overhanging despair of 'is this my life for the next 50 years?'
The nail in the coffin was both of us having exit affairs which was a terrible way to end what had been a great friendship for most of our 9 years together. It has really ruined what might have been a lovely friendship for us to maintain if we'd split up properly and respectfully.
So, please don't repeat our mistakes but instead walk away from this with your dignity and moral high ground in tact. It sounds like he's on a similar page to you anyway, so be brave.
Oh, and yes, I was very worried that I had missed the boat for meeting someone else and having a family but I met my wonderful DP18 months ago and we are very enthusiastically trying for a baby 
.
You are young and have your life ahead of you. Don't sentence yourself to this misery for any longer.
Good luck 