I saw witch hazel recommended on some trans guy's tumblr for this problem, so I've been putting a witch hazel based astringent on my nose and around the edge of my face where my hair falls 3x a day and it seems to help a lot with feeling really oily. That may just be the fact I'm constantly cleaning my face now with the witch hazel, but whatever works. It's not that expensive for a big bottle, it is like 6 bucks where I live, and the bottle lasts forever. I had to get it at the skin care section of a pharmacy though, as my grocery store does not carry it.
In addition to your skin producing more oil, you can also get a lot of the grease on your face from your hair, so you may want to try a new shampoo or something now that you're on T. Also wash or change out your pillow cases frequently, as the oil really can collect there overnight, which means the next time you go to sleep you are putting your face down into a pool of your own grease, which is of course not helpful and gross to think about!