EX GF made me her Cuckold Slave [mf]

Hi guys for a quick info. English is not my main language so please forgive if there are some mistakes.

I M24 and my EX-girlfriend W22 have not been a couple for a good 2 years. However, the sexual attraction from my side is still incredibly strong and I think quite often about the old days and especially about our sex, which was great. (at least for me)
We often talked about the cuckold fetish, but never dared to really live it out in our relationship.
After we broke up, we had more and more conversations about her sex life. She told me all her stories and gave me a handjob meanwhile. Over time she became more and more dominant. For example I was only allowed to come when I say that I have a small cock and can never satisfy them more. Or she ruined my orgasm and laughed that I already cum even though she is not even halfway through her story.
It was great to hear how she had sex with other guys and how much better these guys were compared to me.
I was not allowed to fuck her. The only thing I was allowed to do was lick her and massage her feet. Sometimes she wouldn’t let me cum at all, ruining my orgasm or letting me rub my cock against her leg until I came.
This went on for a while until she met her new boyfriend. She then just told me that he had the biggest cock she had ever seen and broke off contact.
She now lives in another city (about 6 hours by car) and we have completely lived apart.