Hip pain

I’m a 51 yr. old woman. I’m in reasonably good shape…I’ve exercised regularly since my mid-thirties, walking and skating. A couple of years ago, I developed a work-related bone spur on my right heel, so I can’t power-walk like I used to. About a year ago, I began riding my cousin’s old clunker one-speed bicycle and found it didn’t bother my heel spur. I live in Florida so the terrain is flat. I started out riding 3 miles and progressed to 5-10 miles within a couple of months. In April, someone gave me a 12-speed Panasonic road bike and I fell in love with it. I’ve been riding 3-5 times/week, between 10-18 miles each time. Within the last few weeks, my right hip has been bothering me. For the last week, I’ve been avoiding using the drop part of my handlebars (so as to sit more upright while riding) and riding only 5-6.5 miles per time in a very easy gear (only rode 3 times this week), and taking ibuprofen, icing my hip a little, and have started stretching my hip after riding and doing strengthening exercises. The pain seems to be getting slowly worse…it’s in my hip on the side, more posteriorly but not in my butt really, and seems to be somewhat affected by rotation of my hip, lifting my leg (but only sometimes) and lying on my hip. It does not hurt at all during bicycle riding but long afterwards. It radiates down the side of my thigh a bit and I can feel discomfort down the side of my calf, although that could be from my heel spur too, which is the same leg. I also seem to feel it in front of my hip, midpoint between my pubic bone and the exact side of my hip. Sitting on a hard chair aggravates it while I’m sitting. The pain is not sharp at all but very low-grade, like an aching. I haven’t tried heat yet and I’m also going to make sure my bike is properly fitted to me. I REALLY don’t want this to get worse and prevent me from riding my bike. Any advice or similar stories out there? Thanks!