I'm going to leave this open for now because I think there's some good advice generally in here.
If you want to be "liked", the first thing to do is to like others. Don't spam, but do post regularly in other poster's topics with helpful, relevant, supportive remarks. What sort of person do you like on forums? Someone helpful who is always making encouraging comments in modding WIP threads, perhaps pointing out polite suggestions for improvement? Someone who always has the answer to technical problems and can explain it helpfully in a non-condescending manner? Someone who steers Community Discussion threads in constructive directions, answering even "stupid" questions with on-topic advice? Think of the sort of person you would like to hang around and be that person.
The avatar advice is good: choose something that stands out for the right reasons: eye-catching but not glaring, memorable and inoffensive. A personal brand statement, if you like.
Everyone has their "off" days and I like to think that, as a community, we can all be here for each other when we are feeling low and want some support from our friends. That's fine. On the whole, though, try to stay positive and distract yourself by focussing on other people - enjoying their contributions and responding with praise and encouragement - because positivity attracts people far more readily than moping. That's not to say you can't ever complain, but trying to stay positive is a healthy mindset to get into.
Finally, if you do feel overwhelmed and need more professional advice than a bunch of nerdy strangers, look for the mentalhealth.gov link at the bottom of the page. Those are the people who really do have the answers.