Anxiety and Constipation?

I'm 19 and been suffering from bad Anxiety for the past 2 years (but i've had it since my early teens without knowing), and also i've got a panic disorder and suffer from panic attacks regulary.
The only time i actually know i'm stressed is when i become constipated, i'm so unaware of it half the time. So when i get constipated i get even more stressed which proberbly lead's to the constipation lasting longer, so i have to take lactulose to help. I also get spasms in my bowels (mainly the lower left - the colon/rectum) which can hurt. My appetite also decrease's which make's me frustrated because i'm so worried about losing weight because i'm naturally slim and hate it (a big part in my Anxiety) and cos i get constipation regulary my appetite has changed, i'm so fussy now. But ofcourse with Anxiety when i do become constipated i can't help but think i have something more serious wrong with me, which make's me feel worse.
Anyone else have this combination?
I also get other symptoms with my Anxiety aswell.
Any tips?
x

[silverberg]

Yes that can happen with anxiety, and it's good that you are aware of the cycle (bad cycle) that can cause, drink more water.