Bad Odour and Stinky Saliva. What to do?

2 month ago, I started developing a chemical odour whenever I used to eat anything and it also tastes like some chemical , eventually it started getting worsen till now that I can't eat anything because whatever I try to eat will smell me like a chemical substance and tastes also the same. Yesterday onwards, I have starting getting stomach cramps (I took O2 Tablet) but it also didn't helped. Also, to mention me and everyone in our family suffers from constipation and from these 2 months that has also been a part messing up my routine. From midnight, I am feeling quite low and facing these stomach cramps. In past, I got some panic attacks so I was actually on medication precisely (Paxan and Adesure) but as I was feeling better even without them I stopped taking them 3 months before without consulting anyone, now thinking can these be withdrawal symptoms of those and also an important thing from yesterday I have observed my saliva to be very very stinky. Please let me know what to do?