try Protein Bars instead that are soy based- i can't have Protein Shakes or milk based (WHEY) bars - but i'm doing ok - you wouldn't lose that much muscle in such a short time - it's more likely caused by anemia or thyroid issues or an electrolyte imbalance especially if you are not drinking enough- so as others have suggested go see someone and get blood works done. Also beef Jerky, eggs and meat and Beans etc all good sources of Protein you don't really need shakes at 3 months out - they help sure but not 100% needed.
