Right now, the best thing I could imagine you doing, Polymono, is finding or rejuvenating an interest. What was that special thing that made you tick before you met her, or is there something you have always thought about wanting to try but never got the chance before? People who are interested often are interesting to others, too. I would advice against pets, though (tried that!), since they involve much longer commitments than most relationships with people.
Also, I think I might be strongly attuned to polyamory, since I have always felt really strong compersion (delight in seeing your partner show and share their love towards someone else) in all of my relationships, both friendly and romantic, and encouraged my partners to pursue other relationships even if I, because of time constraints, couldn't atm. I think the majority of people, however, come to polyamory after initially thinking themselves to be monos. If you consider polyamory to be a sexual orientation AND practise, there is a very fluid line between identifying as poly and doing poly.
Me: bi female in my twenties