Any and all concerns about medical issues can and should be directed at your doctor! They're the only ones with enough info and qualifications to comment upon this.

Hip growth as a response to feminizing HRT can and does happen in younger patients. Hips don't set completely until the early 20s, so if you're starting HRT at or before then, you can experience both hip growth and your hips shifting in position. Heating pads and anti-inflammatories might help. Be sure not to push yourself too much if you're in pain, and as I already mentioned talk with your doctor if you're worried about the pain level.

My hips have also been hurting for about a year or so and I'm 2 years on HRT. I didn't know that it might be caused by HRT. Do you mean the skeleton itself widens? Do you have any additional reading I could look into on this topic?

I'm also taking medication for ADHD which causes muscle tension and dehydration so my calves are always so tight and I get charlie horses like crazy but that's something else entirely... lol I just mean my entire lower half is in bad shape but I'd love to know if my hips are something I can fix or at least alleviate some of the aching.

i think this is relatively normal and probably the pelvic tilt thing the other poster mentioned. i checked with a transfemme friend and she told me the biggest thing she did was get a new chair that worked with how her body wanted to sit now. she also tries to get up and stretch / walk around more often

aside from those things, you can take over the counter painkillers or try heat on the area, but some of it will just be riding it out, i think