I have osteoporosis too.
Since I have MS I am not very venturesome riding any more, and I mostly ride at the walk. I will ride Arabs since with a lot of them I can make a deal of I won’t hurt you and you will take care of me (that did work with an pretty explosive Arab gelding.)
I will NOT take the biophosphates. From what I’ve read, on the COTH Forum, is that micro-fractures still happen, and they DO NOT HEAL leading to the thigh fractures. Well ever since I read that it has been a NO, NO, NO to any doctor that tries to put me on them. I see no way that I can ride without getting those pesky little microfractures on my femurs. I started imagining little nightmares of my thigh snapping in the saddle from a sudden move of the horse causing me to grip hard with my legs, and not being able to get off with a broken femur. Plus I read that fractures can take twice as long to heal on the biophosphates and that the bone never heals completely leaving a cyst of unresolved bone tissue. The true kicker was that the biophosphates they prescribe stay in the body for years even if you stop taking them.
Unless there is a million percent guarantee that my hip bones would never break I really cannot see taking the risk. I was almost sucked in, and I am so glad that I read the Forum here. Twice as long for fracture healing means around 3 months, and I would totally loose my ability to walk, maybe forever (MS weakness.) Before I got back in the saddle I had degraded to needing a power wheelchair, but after I started riding again my wheelchair wore out finally and I never had to replace it. If I do not ride I would probably be in a nursing home, a total burden on my family and society.
So when it is cool enough I use a protective vest. I wear pads over my hip joints. I have the Rider Grips on my saddle, the RS-tor riding aid, and Tech Venice safety stirrups, as well as the Trauma Void helmet which helps protect my neck from getting twisted. Nowadays I always ride in silicon full seat breeches to help keep me centered in the saddle. I ride in a ring with deep sand.
OP, I am sorry you got diagnosed so young, that is a true bummer. I was diagnosed with osteopoenia (sp?) in my 40s, and I was diagnosed with full osteoporosis a year or two ago. I just decided I had a new goal in life over all others, to keep riding horses until the day I die.
One of the problems is that the MDs either do not know or do not care (kickbacks?) of these side effects of the biophosphates, and they will unrelentingly terrorize you into taking them.