Prolotherapy is not particularly painful. The ligament that requires fixing is given shots ... usually like sugar water ... along its whole length. Local anesthetic is used. That is it. The idea is to shock the ligament into self-healing. Sometimes our highest level of healing doesn't turn on properly so this process gets its attention.
For me the process took 10 days for the ligament to tighten and it happened at night. Popped back like a rubber band and woke me up! ... but I understand that is a bit unusual. Some people require several treatments. I suspect that has something to do with the state of our own systems.
Prolotherapy is not covered by our insurance but is certainly worth a try. As Dr. Johnson says ... to diagnosis a Lax Ligament requires physically examining it, but it is easy to feel it is lax and not able to do its job. An Xray doesn't do it!
Hope you can find healing.