There will always be people that seem to be more successful than you by some measure(s). Now, instead of envying them, you could try to see them as an inspiration. If you can't, the other option is, quit comparing! It seems a sure way to ruin you self esteem and make you unhappy. You are a unique person with wonderful qualities, if only you could stop beating yourself up long enough to see them. Experiencing set backs, does not make you loser. What matters is that you learn from your experiences, and keep going forward. I know it's hard. Try to be kinder to yourself. No more telling yourself you are a loser, k? Try reminding yourself of your good qualities, the good things in your life, do something you find relaxing for yourself, etc. Take a break if you need it, but please don't give up hope or quit trying.
Wishing you the best, Jan