If your looking for forums to post on, try a google search of forums or blogs in your niche, even other IM Forums. Comment/post on anything relevant to your niche. These things should help you drive some traffic. You can also try sharing your videos on Social Media Networks. Good luck to you
You need to increase your followers, you can also consider creating other social media accounts to increase your followers.
Maybe you can create your own site featuring your channel and the topics you are talking about. You could then funnel the traffic there which would then be redirected to your youtube channel. I've seen it done before.