I have trained in boxing and or Muay Thai throughout a good portion of my early teenage years, I am 19 now and have had a tough few years regarding my mental health and have been struggling with some substance abuse but am doing better now. I feel It would be good for me to get back into training. However I am anxious about joining a gym because of potential judgement from people I know already in said gyms and or people that know me. If I joined a gym and stuck to it would people generally accept me or would they judge me for my past of being a loser and a weak person and poke fun at me? Also is it too late for me to start training again and possibly fight, I have done muay thai for 2 and a half years, starting when I was around 13 and doing various boxing classes in between then and now but never really sticking to it due to lack of discipline and self esteem.
With your life dilemma, just put your best foot forward , then bring your back foot forward the same distance, keep that solid balance. Who cares what other people think? If you are embarrassed about your past than forget about it and keep moving that good foot forward. What you did for your body, while you were young, will pay dividends in your development as a boxer. I hope that you are the young newby that I just met. I worked with him while he was the bag for a tttle while. He was just touching the bag with his right hand, he jab was good doe. I said put the back leg behind it and watch the power that you'll generate. He did that a few times and I honed it in. The power that he felt in the new shots excited him, I could tell. Teaching boxing to kids brings me joy.
Have a go, be respectful, train hard and you will improve your self confidence. Training was a gift for me. Whatever your circumstance is, you definitely can do it. If you can put together 5 years of solid training at this time in your life, you will enter your full adulthood with the ability to defend yourself and healthier as well. As far as the self esteem issues, I have suffered there as well. It is always better to go for a run, hit some push ups and drink water than an alternative route. Conduct yourself with respect and don't bring any trouble into the gym and you will be absolutely fine. I'd say go for it.