You should definitely try to get some new affiliates so they will promote your site. I would not recommend to use any free blogging platforms because they are not stable and they may ban adult sites at any time. You can, however, buy your own domains and create simple blogs or tube sites on WordPress. It requires lots of work, but after a few months, you should get some great organic traffic.
Why not get some ads on the most authoritative sites in your niche? Find them if you have not done that already and ask them if they would sell an ad spot or they may even join your affiliate program page.
Feel free to also read this topic on this topic:
How To Promote My Adult Paysite