How to cope not successful in age 20-30?

28M im single and unemployed, for 4years im unemployed and mentally in a dark hole. To worsen it my ex got married to an rich fellow from another country and migrated. It hurts like hell, i dont have the one it is syndrome, but this ex was specifical, i was unemployed when she wanted to marry me, but i was broke and unsure of my future and i knew about hypergamy and girls wanted a thrill and excitement in life, so with my broke ass i couldnt afford a proper meal for her when dating so i didnt wanted to make it worse to her by marrying or promising a marriage. So fighted with her over a small issue and rejected her saying I don't want her when I literally wanted her, i was afraid of hypergamy kicks in later and she will leave me in the middle of a marriage. I rejected her and i cried silently for over years while cursing on my self for not being successful or at least not having a job. It is depressing. But i still cant forget my self for not having any sort of life or financial capacity , i still dont. Im envy of her marrying a rich fellow than me while i have to work for years and marry at a late age. It is depressing and sucks. How to be a rationale male about this?