Quickly checked your a4a profile and that looks fine. Good photos, clear statement re: what your after. I'm a bottom but if you were in my area and approached me I'd be tempted to try breeding you. Only possible negative is some people will be put off by you saying you like pnp. That said if pnp is essential for you keep it in there.
You mentioned posting ads. In my experience these can be a crapshoot. Many times I'll spend days posting ads trying to set something up only to get nothing.
As intimidating as it can be I find being proactive is key. Do a search for profiles and send a message (not an oink/wave, lots of guys ignore those) to a bunch you like saying you're interested. Don't just focus on one guy. If they don't respond, move on.
Most important is to try not to take rejection personally. Taking myself as an example last month i was in a hotel and messaged tens of guys to set up a quick session. Most never responded, 1 gave a hard no, a few talked a good game and flaked. All that said I did get 2 to come over and breed me propper and am hopefully doing more with them in future. Point is even though most of my attempts failed, by casting a wide net I eventually caught a few loads.
All that said remember that online dating is hard. 90% of the time you're going to be dealing with rejection. Since it's not face to face people are more likely to overlook you, make snap judgements or be an asshole. For every party add that got 10 or more responses in an hour I guarantee there were dozens more that either had no responses, a bunch of flakes or were canceled last minute. It can be demoralising. If it's giving you nothing but grief step away from online and try other things (bars, saunas, lgbt events). It might be what you need.
Good luck