“What can I do for piriformis syndrome?”

I would recommend trying a piriformis stretch and fire hydrant exercises. Videos demonstrating how to perform both can be found on Youtube.

Heat is your best friend when you can't exercise due to spasms

Sorry to her about how bad your pain is! I'd recommend sciatic nerve glides and piriformis stretching and prone press ups. Here are a few youtube links of those: https://www.google.com/search?rlz=1C5CHFA_enUS931US933&sxsrf=APwXEdfn0S1sh6NMqNA25pmHuOFD-5r3Kg:1686483564243&q=sciatic+nerve+glides&tbm=vid&sa=X&ved=2ahUKEwillpDukLv_AhU8lWoFHV8fA6MQ0pQJegQIChAB&biw=1311&bih=687&dpr=2#fpstate=ive&vld=cid:43a771d2,vid:XP1yzpFR6ho
https://www.youtube.com/watch?v=8oPHrX_oALk
https://www.youtube.com/watch?v=UqSP7ZrHxRE

Hope these help until you get into PT!

You could try working on the muscle with a tennis ball against the wall to help decrease the tightness and spasms as well as some gentle mobility: laying on your back doing some gentle hip internal and external rotation, hamstring stretching, if tolerated gentle hip flexor and piriformis stretching, and diaphragmatic breathing.

Some other means to manage your pain and symptoms more conservatively would include heat application followed by gentle hip external rotation stretches. Then followed by ice pack application to reduce tone and muscle spasms. If you are experiencing symptoms that spread into the legs "pins and needles" this may indicate the muscle is compressing the sciatic nerve in which case gentle ROM exercises or nerve glides can help. Please consult a physical therapist in your area that is familiar with orthopedic conditions to guidee you through treatment

Diagnosis of Piriformis syndrome is very broad and does not specify the reason for your problem. It is very important to determine what causes your symptoms in order to address them. History of the injury, mechanism of the injury, past activities, posture, mobility, your neurological and mechanical status, how you walk, and special tests are important in finding the reason for your complaints. Please see a qualified and experienced Physical Therapist who will spend time with you and answer your questions. Do not settle on the quick screen or short visit in the very busy clinic. Demand certified manual therapists and quality care. You are the customer and your insurance reimburses for the rendered services.=20
Reasons could be many: direct impact to the muscle, your SI or your hip joints could be mal tracking, you could have slight dysplasia or small functional rotary dysfunction in the thoracic spine, you could have T-L junction or lumbar spine dysfunction, you could have problem with your knee or ankle on either side (old sprain/injury), etc.
Before you see somebody you can try finding a comfortable position (back with knees bent, either side lying with a pillow between your knees, or stomach on your elbows) to find some relief, little movement is better than no movement and using heat (chronic condition - more than a week) or cold (acute condition). Be sure to use a protective layer between the heat/cold agent and the skin. You could have a sensory deficit in the buttock area and hurt your skin.=20
Taking care of your body is the best investment you can do and it will pay off for the years to come.