I weigh more than 300 pounds and am bipolar and have been deeply depressed for more than a year. Yet my self esteem, oddly enough, is pretty good. I think a major reason is I have done stand up comedy for more than two decades. Occasionally I do "fat" jokes but not very many, they are rarely stereotypically self deprecating. They're often absurd too. Mostly I cover topics that any comic would. If someone is dumb enough to heckle me they get slammed and thoroughly embarrassed. (And my opening routine is unique and intimidating enough that hardly anyone dares to try to heckle me!) What do I care if they think I'm fat and ugly. I try to have the same reaction if someone says something on the street, though in NYC it seldom happens anymore. I got a lot more flak in my 20s than now that I'm almost 55. Can you train yourself, when people call you names, to say "What makes you think I give a rat's ass what a moron like you thinks of me?" Or an equivalent phrase in French? Some people will respond but I bet the vast majority will be stunned into silence. This will help your self esteem immensely and give you back your power. Also do they have anything like what in the US are called meetup groups? Where people who have a common interest get together for a few hours for a shared activity. There is a meetup group for virtually any interest. People are likely to be friendlier in one, or certainly unlikely to be hostile. Check the Internet to see what exists in France. One specific activity I recommend to bring you out of your shell is an improvisation class. I wouldn't start with that, but after a few months of going to groups give it a chance. It's fun and in beginning classes pretty much everyone is nervous they'll mess up so you won't be alone. A good instructor encourages you to just have fun. It'll take a lot of effort to overcome a lifetime of unhappiness but it can be done. If you're not in therapy consider that too. Hope these suggestions help. Best of luck.