I left my old company. If I go back, will you? If your family doesn't support you, your former colleagues will laugh at you behind your back and call you stupid.

These are all your own guesses. For your own affairs, only you care most, and others won't care too much about you at all. You are afraid that others will laugh at you, but in fact, people don't care whether you stay or not. Everyone only cares about their own interests. If you are very capable in the company and are invited back after leaving, other colleagues will only flatter you and will not laugh at you. If you can't get up outside and want to go back, there's nothing to joke about. Who hasn't been in trouble? Smart people know very well that one more friend in the workplace is better than one more enemy. If there is no stake, why should we look down on you?

So, if you really want to go back, go back safely and don't care too much about other people's opinions. The problem is not others, but yourself.