AS concerns and questions. Recently diagnosed Iritis.. 22 years old and VERY worried. Please help!!

Hello,  
I am 22 years old, and have had back problems for the past 4 years or so.  It started with pain in my low back.  I had a very old and non supportive mattress and when I bought a new one the syptoms (symptoms) went away, so I disregared the issues I was having.  Last year, I experience severe SI joint pain (to the point where I couldn't walk)  This only occured for a month or so, and I evenually found some coping techniques.  I still have SI joint pain every few weeks or so , but it's pain I can deal with. I have a very stiff mid-back upon waking, but this doesn't happen everynight, and it usually goes away with stretching in themorning.  I found a physical therapist, who ordered some x-rays and noticed a slight curve in my spine.  She can also see a possible leg-length difference.  She said that is is why I might be having the problems that I am having.  Since I have been working with her, my symptoms have seemed to improve.  I am in the process of seeing if I have a true leg length difference and if I do, getting a lift..
HOWEVER today, I went to the eye doctor and was diagnosed with Iritis.  I am probably the biggest worry-er you will meet and make myself sick worrying about things, so I would really take any reassurance that you can give.  He told me that this (iritis) could be caused by an underlying condition.  I went online to do some research, and found this somehting called AS.  I seem to fit the symptoms and now I am worried sick when I read how badly this affects people. I have no history of this in my family (at least that we know of)  What are the first steps I should take? If I DO have AS will I live a long healthy life? Be able to have kids, play with them, travel, etc? Are there different severities of AS? Could my iritis be unlinked to my joint pain? (I read that some 50% of cases are un-related to rhemetoid issues and many times one doesn't know why they got iritis, even after they get tests done) I should mention that I only have 1/2 a thyroid (I have a partial thyroidectomy due to a no nmalignant lump) So now I am hypo thyridic. I also am anemic, but I don't eat meat.  Anything you can do to ease my mind at all or clarify things would be greatly appreciated!! Thanks so much

[txsilver]

I understand worrying and scaring yourself with too much info online because I did it too.  First, you should make an appt with a doctor, probably a rheumatologist - did your eye doc refer you to one?  You need to find out if you have an underlying condition like AS or one of the other conditions in that family.  
It is important to recognize that everyone is different and some of us get mild cases of these diseases while others are more severly afflicted.  The descriptions you read online are often worst case scenarios with all possible complications listed.  Also, with treatment, many of us are able to avoid the worst case.
I tend to plan for the worst and hope for the best so I can understand being compelled to consume as much info as possible.  Try to temper that urge.  There are over 100 different types of arthritis and innumerable autoimmune conditions and many of them have overlapping symptoms.  Try to break this into baby steps and keep us posted.  We will help you through this.