You are really doing a lot of guessing here. You do not know these women are not turning into long term relationships because of your speech impediment, in fact you readily admit that no one has told you that. I would find it very difficult to believe that THAT ALONE is why you have never had a long term relationship. More than likely it is the lack of confidence. I have never had a conversation with you and don't know you at all but what I do know of you (ie: what you've let me know) is that you are not worth knowing because no one likes you because of your speech impediment. Do you see where this is going? You said in the other comment that it always starts off well, then they "pick up on your speech impediment later and are turned off by it." Really? Do you really believe that they don't pick up on it immediately? Your confidence is your problem, and that is fixable. Tell yourself that you are a good person, you are likeable and that you deserve happiness, and the confidence will come naturally.