Period pain severe enough to make you cry or feel faint isn't something to just push through, even with otherwise regular cycles. This degree of pain with a light flow can point to primary dysmenorrhea or sometimes endometriosis, and the stress you've carried this year can make the pain feel worse too. The hair shedding and quick weight gain are worth checking alongside this, since
thyroid and hormonal shifts often show up as exactly this combination.
Next Steps
Please see a gynaecologist, who can order a pelvic ultrasound and a hormone and
thyroid panel to look for an underlying cause, and suggest safe pain-relief options beyond basic painkillers once they've examined you.
Health Tips
If you actually faint, or the pain doesn't ease with rest, get seen the same day.