A woman's menstrual cycle DEFINITELY affects her IBS. Medically proven. It has to do with our hormones.
You should DEFINITELY see your doctor and consider getting a referral to a GI doctor.
You should also see a naturopath and go through an elimination food challenge diet. This can help you further determine which foods or combination of foods are aggravating the problems with your IBS. This is one area your conventional doctor will agree about. Seeing both doctors in combination like this is referred to as integrative medicine. It is very helpful.
There are some herbs and even simple nutritional supplements that will help both the anxiety and the IBS. Often GI doctors write prescriptions for anxiety medications because it's proven to help IBS. It has to do with the seratonin. This is whether the person actually has an issue with anxiety or not. Often, though, we do have anxiety issues and this definitely impacts our IBS. Especially for those of us with GAD or other anxiety issues. I think you'll find that it's helpful tha the family practitioner and/or GI doctors are able to write prescriptions for these medications, because it means one less specialist you have to see when you know what you need to try as far as medications are concerned. GI doctors also know which ones are more likely to help with your specific IBS symptoms than the shrink would be anyway. At least that has been my own experience.
By the way, if you're not already taking an antispasmodic, you should be. Since you have an anxiety disorder, you will likely find Bentyl to be very helpful to use as an antispasmodic. It is sedating, so it should prove helpful with the anxiety issues as well.
Estrogen also promotes problems with elimination... You might ask your GYN to take some estrogen levels and see if that isn't adding to your whoas.
It's the reason why men are always so regular and women are always so constipated (unless they have IBS).