@Birdofparadise8 not silly hun, this is obviously a source of distress for you. If it matters to you, it matters.
This, to my mind, is similar to how I used to behave and for me it was strongly related to my anxious/preoccupied attachment style. This is the preoccupied bit. For me, changing the behaviour involved having to implement strong boundaries with myself - e.g. not letting myself look at my phone every five minutes or feel compelled to reply immediately to every message received.
Something I think is important here is that you're noting that this behaviour is heightened when you're distressed, and that if you don't get responses your anxiety starts to spike. Perhaps that's a place to start - looking at this cycle, and thinking about implementing other activities to engage in when you're distressed. Either don't post on forums at all, or if you do, make the post but then leave for a while to focus on self-soothing or distraction until you're feeling more regulated, as opposed to feeling glued to the refresh button. When you do want to return to forums, check in with yourself - if you've gotten no replies, will this make you feel crappy? If so, is it a good time to return to forums? Is there anything you can implement to help you stay within your window of tolerance? And similarly, are there ways you can reassure yourself - i.e. say no one has replied, if your brain defaults to that being a reflection of you and your self-worth, how can you remind yourself that it isn't? Remind yourself that others have their own lives and their own stuff they're dealing with? And remind yourself of all the many other occasions where folks have taken the time to respond? Stuff like that.
Just some thoughts, please don't see this as a step-by-step manual or the only way to go about this, it's merely an idea based on my own past experiences, and it may not go the same way for you since we're different people. But I hope there's something in there that resonates and gives you ideas anyway 😉