Brief Answer:
Sacroiliitis is completely treatable

Detailed Answer:
Hi dear and thanks for your query to HCM.

I have read your question and reviewed all your reports and understand your health concern.
I'm sorry that you have so much pain.

Please don't be so pessimistic because Sacroiliitis is completely treatable .
From your detailed history, it's mostly favoring sacroiliitis ,
Pregnancy ,
Pubic symphisis diastasis ,
Fall from stairs

Hence try to take all medicines that have prescribed doctor and follow these tips :

A short period of rest may help calm the inflamed sacroiliac joints.

Heat and/or ice

Warmth or cold applied to the area will provide local pain relief. Application of a cold pack will help reduce the inflammation in the area. Application of warmth, such as a heating pad or hot tub, will help stimulate blood flow and bring healing nutrients to the area.

Sleep position
Changing one's sleep position can help alleviate pain while sleeping and at waking. Most patients find it best to sleep on the side, with a pillow placed between the knees to keep the hips in alignment.

Please feel free for any further question, i'll be glad to clarify further.

Regards

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Brief Answer:
You can try with physiotherapy and below exercises

Detailed Answer:
Hi dear again !

While you have three months that you are on bed you can try with physiotherapy and exercises .
Exercises you can try at home are some:
1.Chest to- knee stretch
Lie on your back with your legs extended. Exhale as you draw one knee to the chest and hold it for 5-10 seconds. Inhale as you lower the leg back to the mat and then repeat with the alternate leg. Continue this process until you have completed 8-10 repetitions per leg.
2. Knee Rotation
To begin, lay flat your back with the knees bent and both your feet flat on the floor. Repeat this process on your right side. Continue this process until you have completed 8-10 repetitions for each leg.
3. Bridge
Lie on your back with your knees bent and the arms against the body and palms against the floor. Squeeze the buttocks and raise the hips off the ground to bring the torso into a straight diagonal line. Hold this position for 5 seconds then slowly lower yourself back to the ground. Repeat 8-10 times.
4. Cobra
Start by lying on your stomach. Slide your hands beneath your shoulders and push up, extending your arms and bringing your upper body off the floor while keeping your pelvis and legs on the ground. Hold this position for 15 to 30 seconds, and then slowly lower back down to the floor. Repeat 3 times.
6. Child’s Pose Stretch
Make sure your knees are spread apart and rest your buttocks on your heels. Extend your arms with your palms facing down reaching as far as you can. Hold this up to a minute and repeat in between stretches as needed.

Some exercises to avoid would be:
Crunches or sit-ups
Any exercise or activity that involves a lot of twisting or turning at the hips such as golf or tennis
Heavy weight lifting, especially those involving the lower back

Shooting pain with lost sensation in your left leg is due to oppression of left nerve from inflammation of around tissue ,therefore you take nevramax(it used for nerve damage).

Pain is caused form some factors:
Pregnancy
Pubic symphisis diastasis ,
Fall from stairs

Don't worry because you will be fine and you will try for another baby .

Best regards

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