Very serious situation.
You are only 20 weeks
pregnant.
Please consult with your Gynaecologist. There is no specific treatment . But patients are treated with Amino drips, Arginine sachets, and a high carbohydrate high protein diet.
No one can get oxygen for so many weeks. Nor the bedrest be imposed for so long.
The treatment can't be taken at home. So you have to talk to your Gynaecologist.