I've always had the best relationship success when I stopped looking and started focusing on making myself happy with my life, the way it is, or else changing other aspects (career, housing, etc) that were holding me back.
That being said, now that I've been married for a few years, I really do enjoy having people in my life to share my successes with, and to get support from during my failures. So I can empathize with the feelings of loneliness and desire to share your life with someone.
I wonder, though, if looking for an equal three-way relationship will be the "easiest" way to find companionship. Those relationships are pretty difficult to establish, and anything that's difficult will inevitably take longer to accomplish.
I met my husband at a party hosted by a shared interest group, so I definitely recommend "join a group" as a good way to meet people. As a bonus, until you meet someone, you'll have fun sharing your interests with people who like to do the things you like to do.
I met my girlfriend on OKC. I had just thrown up a profile for fun, not really looking but wanting to be more "available." I specified being poly, I answered a ton of questions, making sure to rank "high" those questions that would exclude mono people and people with values that were completely out of line with my own. Auto messaged me, she was just getting back in the dating game after taking a year off to focus on her marriage. We clicked right away. So, I also recommend "being on" OKC but not necessarily hunting on it.
“As I am sure any cat owner will be able to tell you,
someone else putting you in a box is entirely different
from getting into a box yourself.” —bisexualbaker