First 70.3 Swim Fail!

So unfortunately my first 70.3 ended in a DNF. My training was going fairly well (not as great as I would of liked but what I thought was pretty good) until about a month and a half ago. After a long pool session I started having alot of pain in my shoulder. Unfortunately for me this shoulder is a problem shoulder from an old injury but tends to only flair up sometimes. I took it easy from swimming for about a week and a half and got back in the pool for a nice easy "test the shoulder day" I felt ok that day but had pain the next day and decided my best course of action was just to rest it. With only a month before my 70.3 I was unsure what to do.. defer to next year (probably best plan) or rest it til the race and give it my best shot. Well of course I opted for the second option. I continued with bike and run training and just hoped for the best for race day that I could get through that 1.3 miles. Well race day came and I felt pretty good. Then I put on my full wet suit and immediately thought I hope this doesnt actually make the stress on my shoulder worse.. well I made it through the first 1/3 of the swim and thats about all it took. Shoulder was in a good amount of pain. I tried breast stroke but it didnt help much. Swam over to a lifeguard and got taken in. At this point im feeling pretty bummed out and tried to decide wether to do the bike/run portion. I figured I've already paid and drove down for the event.. I might as well at least do them. So after a quick stop to let the GF know I was alive.. I continued on the journey. In retrospect I'm glad i did instead of moping around being bummed out. I'm still mad I didnt completely finish but I should of known going into it.. that the shoulder wouldn't hold up. Lots of great volunteers helped to make the day good after all!! And now i have an appointment to get the shoulder looked at and hoping my tri season/surf season isn't over so early in the year!!