Let's see...what can I say that will be of help.
1) You're going about this the right way. You're writing consistently and productively. You've finished projects, then moved on to other projects, rather than just sitting around and waiting to sell. For that, I say good job! I think this is the most important lesson to learn, and you're way past it.
2) I'd suggest staying away from writing entire trilogies. Now, it CAN work. Rothfuss had his entire trilogy completed when he sold the first one. It can get you a better contract once you actually get an editor interested. The problem is, it's much harder to get an editor interested. Let's say that instead of writing a trilogy, you'd written three first novels in three different trilogies. You could now be marketing three different books to three different publishers and increasing your chances of selling threefold based on sheer percentages. Instead, you've got one property that you can be sending out, since you can't really send book two to an editor after they've rejected book one. You could, however, send them book one of a different series. Just helps you beat the odds, but it's by no means a hardfast rule.
3) Another thing you seem to be doing right is networking. If you're really, really serious about this, then I'd go for it even more. Attend Worldcon, World Fantasy Con, or other big conventions and start to learn the names of editors. Follow the business; read Locus and learn who is selling what. Learn who is buying and what they're buying. Try to meet editors at conventions. Read their blogs. In other words, become more than just a writer--become a business person. If you hear that editor X has moved from Tor to Baen, but didn't take many of his authors with him, you'd know that this is an editor who might actively be searching for new authors. That's a good person to target.
4) Just keep writing. I was working on book 13 when I sold book 6. It took me nine years of dedicated writing before I had a book come out. You have to be in for the long haul. Don't give up. Keep honing your craft. Keep writing. Keep asking for advice.
And, if you happen to be at a con or meet an author, offer to buy them lunch in exchange for letting you pry them with questions. Everybody likes free food. (Though, I'd probably get together a buddy or two and say "We'd all like to take you to lunch" so that you're less threatening.)
Anyway, that is pretty much the road I followed toward getting published.