First off, you haven't actually made or bumped a thread in seven months before you made this. Anyone who goes digging through your post-history may find something like this offputting if you're already complaining before having tried again in recent memory.

Second, put in effort yourself. Don't wait blindly for someone to take a hit on your interest check. Go look at other people's stuff and PM them, too. 

Third, if you're only doing 1x1, you're especially likely to get drowned out. 1x1 is not only a crowded market, but also, if you don't already know someone, it's going to be insanely hard to find someone you're compatible with. It's the most wild west of all the sections and can be incredibly hard to find a like-minded individual in.

My suggestions are:

-Don't really begin about your age unless someone asks. It's not info we need to know up-front, your skill as a writer isn't dictated by how old you are.
-Try not to talk about yourself as an individual in general (at least, outside the status bar) because people don't really care unless you become friends with them. It comes off as overly familiar.
-Try to join or make group RPs before going into 1x1 so you can meet people and get some contacts on the guild.

Also, try to avoid telling other people up-front what they should be like in your check. Just describe what you're good at / looking for and then leave it. The less you tell people what to do, the more likely they'll be to want to give you a shot, because then it doesn't seem like you have this pre-conceived notion of mistrust to the general public at large. By differentiating between a 'serious' and a 'non-serious' RPer, you're inherently putting people into one of two camps and asking the question "Oh, so what do [i]I[/i] fall in then?"

Simply put, by assuming something of someone else, you're shooting yourself in the foot. You plant the seed of doubt in their head, and they may in turn think you're a problem player yourself. Don't be that way.