Well, it depends. Often I see people ask for this who want to take but not give, which can get you banned in the best case and destroys a community in the worst case.
Loneliness often comes from particular experiences like not being able to share good things or rant about bad things.
But that is a symptom, not the cause. The cause is missing connection. There are possible neurological reasons for connections deteriorating (i would know) but if one makes themselves aware of this, they can try to counter this.
If you want to be listened to, related to, helped and understood, you need to do that for others. The rest will mostly come on its own. If that does not come naturally (again, i would know) you have to make an effort to do it.
After that is clear, I would suggest chat groups, not forums as forums are much more loose and dont allow for a deep connection imo. Depending on your personal identity, you can find chats which takes a thing you all share and makes it a topic to connect about. I suppose participating for a month will get you decent connections to share outside experiences with. Again, it needs to be mutual to work.
I hope this helps. Have a nice day.