How to not lose confidence over the fact that you cant get a girlfriend and have an intimate relationship?

I am 28 years old. I am proud of my life when it comes to career, money, travel etc. and would not change a thing except the fact that I am single.

I feel like everything I have achieved or learned up to now means nothing that I am worthless if I am not in a relationship because that would mean I am unattractive to women. It feels like I am failing the main goal in life and no matter how much I hear I can have a fulfilling life without it I know that is not true.

I envy people who are in relationships and believe society treats these people as more successful than single me.

I feel jealous when I hear my coworkers getting married or having children because they have found someone to share their life with while all my days being happy or sad are kept inside myself with noone to share but to myself in the shower. Sometimes I feel like crying because I want the emotions of the day to get out. It has not happened as I try to be stoic but sometimes I wish I let it happen.