Try a pelvic floor physical therapist. You should be able to increase width over time, unlike depth which often loss of depth is permanent. It will likely require time, patience, and some amount of pain, depending on your situation. A gynecologist might also be able to help using cortisone injections under some circumstances. The real issue is usually finding providers with experience with neovaginas.

I ended up with severe scarring and wasn't able to get much width at all, but I just recently had some revision surgery and I'm hoping it will help, but I'm currently working on it. Mostly what helped me outside of stretching tissue, which I wasn't able to do with the scarring, was muscle control, learning to relax them and do reverse kegels.

My biggest issue is the difference in sizes between most dilators is too much to allow for good progressive stretching. I found a device called Milli and I had some limited success with it. However it is tapered a little too much for what I hoped and it doesn't apply equal pressure around the vagina, but has 4 pressure points from the expanding arms. It is the only medical device I could find of its kind, though. I have though about getting one of those inflatable things marketed for training for anal sex in some sex shops, but not too hopeful. My general routine right now is to dilate twice a day, once concentrating on width and another on depth, but I'm still healing from surgery so I have been avoiding too much pressure so I don't tear any sutures and cause more scarring.