hi,welcome to HCM
i understand what you might be going through...
ok,lets discuss and solve one at a time...
1..thyroid problem which might be causing bleeding p/v,,
irregular periods,wt.gain,disturbance in apetite and digestion..
so get a thyroid profile diagnose whether hypo or hyperthyroid and get treated accordingly
and follow physicians advice
2..brown discharge and bleeding after sex can be due to vaginal infections(bacterial,fungal,chlamydial..or cervical polyps,
dysplasia,malignancy)
consult a gynaecologist to examine you ,get endometrial.cervical punch biopsy,
vaginal discharge analysis,
pap smear...and proceed accordingly
i suggest you to donot worry,eat properly healthy nutrtion,maintain general condition fit,follow drs advice
bye take care..