nothing went wrong and yes you didn't do as well as you thought but again no reason to quit. with your score it's true that it will make it rough for you to get matched, but with good score in CK and if your other apps are strong, you still have a shot to find a spot in less competitive field. step 1 is just one of the criteria among many. try to do well in ck and strengthen your other aspects and take time if that is what has to be done.
check out this post:
I passed step 1 with a 192/78. Thought I was toast. Busted ass for step 2, got a 234/95. Out of about 40 applications, had about 20 interview invites, accepted 12. Some were decent Uni, most were low level Uni or strong Community programs. Wound up at my first choice.
So, barely passing step 1 will hurt, but it won't sink you. Things to do:
1. Make sure you application is as strong as it can be, otherwise. Get good grades, etc...
2. Crush step 2, show that your step 1 score is a fluke. Step 2 is often looked at as more important (if you have it) because it tests more relevant material. Additionally, the program may not care that you know the material on either step, but they do NOT want somebody on board that is a "poor test taker" or that will fail in service exams. So, make sure that you demonstrate good knowledge of clinical science, and an ability to pass standardized exams with a strong step 2.
3. Demonstrate a sincere and personal interest in Ob/Gyn with your personal statement, your extra curriculars, and your research interests. A student that is weaker academically, yet geuninely interested in the field, and excited about it, will often times get ranked ahead of the student that is strong academically, but shows less interest, drive and desire
4. Get strong LOR's from Ob/Gyn faculty that verify your ability and interest in Ob/Gyn
All this being said, ob/gyn is still not the most difficult field to match into. Any US grad that passes exams and graduates can likely find a spot somewhere, at least in the current market. But, competitiveness increased markedly this year, from not competitive at all to on the low end of the middle range of competitiveness. With work hour restrictions and (hopefully) malpractice reform, ob/gyn could be on the upswing in popularity. So, by following the above formula, I think you can put yourself in a strong position to get a decent to excellent residency.
Best of luck