The white-grayish patches in your mouth can be due to your tobacco & drug abuse
. But weight loss
, painful swellings in the groin, arm pits... suggest that your lymph nodes are tender & enlarged, which is related to either malignancy or chronic viral infection. I support Dr B.R. Naik's opinion regarding your health. Drug abusers are very prone to HIV infection. I advice you to get your HIV test
done along with complete blood and urine tests. FNAC test of your lymph nodes & chest X-ray, to diagnose TB. Till your test reports come, just pray to God that you don't suffer from any incurable disease. Quit smoking
& drugs, lead a healthy life style. Keep away from drug abusers. Consult a good psychiatrist
. My best wishes are with you. Take care & get well soon.