Hi There... I'm 23 Weeks And 3 Days Pregnant. I've

Hi there... I'm 23 weeks and 3 days pregnant. I've been in and out of hospital since 20 weeks as I had proms (waters broke). Ever since I've been out I've had the worst headaches ever that don't seem to go away at all. Severe back ache and stomach ache, and severe nausea and dihoreah for the past 1+ week, is this a problem or will it go away on its own, back in hospital tomorrow for another scan and check (in 2-3 times a week)... Should I be worried?.