How do you let go ?

I'm 48, h'es a 52 yr old pastor, for 20 mos. we were close to the point of marriage , now an 23 yr old young woman has come in our congregation , and his eyes are on her now , till desire shows, I don't know how to feel , I gave up everything to relocate , to be in his ministry with him, now it seems all is in vain, she is young, physically attractive, that's all she has to offer , but I have the skill and ability to minister to him 3 fold body, soul ,spirit, with my attractiveness., do I lat go , are let this play out or will it ?