You, as a unique transgender person should be able to be with someone as unique as you are. We may be part of a tiny minority of the population but perhaps there is someone out there in an equally small segment waiting for you. Let's face it, being in a less than validating situation is inferior to being on one’s own which means you can take your time and wait for the right train to arrive.
There is no right age for this and, just as it is not too late for anyone to transition, it is not too late to find the right partner if that's what you want. Just keep telling yourself that you are worth it and wait for someone who believes it too.
NB: my doctor's other transgender patient who was finally transitioning at age 64, just had her GRS and she sent a note to the receptionist saying: "It's a girl!"