I absolutely do not mean to diminish your pain or discount your experience, but every medical procedure comes with risks. Skin closures (sutures or otherwise) can be done correctly in the first place, but it is possible for the suture knot to come untied or for the suture material to break, and infection is the main risk for any procedure that breaks the skin.

To others reading this: the vast majority of physicians are competent professionals that always do the best that they can, but things can go wrong even if they do everything right. If a physician has one complaint against them for a poor outcome, that's pretty normal. If there are no complaints at all whatsoever, they probably haven't been in practice long enough for the statistics to catch up to them. If there's a pile of complaints (especially ones that cite carelessness or callousness) that would be one to be wary of.