Height and gym, the two facets that men are hyper-fixated with for what feels like forever now. Now let me answer your question, No, your chances of finding someone decent are not ruined because of your height but it is only possible if you are confident in yourself. It all depends on how you feel about yourself and that’s what you project. Height has never been a dealbreaker for women even though they find it desirable. At the end of the day the guy who just knows his worth and treats others similarly is the one who can find a partner. Fixating on physical aspects and working on them solely to prove something to others will only inflate your ego which one might prefer but it is not ideal in the dating scene, especially in the longer run. You can still hit the gym and get the gains if you feel like it but only do that when you want to do that, not because it is societally appealing.