Hi, I'd like to help you with your question.
There are two ways to go with this. One, you can look at it as bad judgment on his part and let it go. If it was a one time incident, then he probably will not do it again. If he said he was sorry and told you why he did it, then owning up to it shows he is serious about not doing it again. He may have been so worried about impressing you, especially given your education goals, that he may have felt that you would accept nothing else. That is not necessarily your fault, it was just his perception.
On the other hand, you did have to find this out yourself. He did not fess up on his own. That can mean he was ashamed of his lie or that he lies about other things. Have you caught him in other lies? Has he given you other reasons not to trust him? Your answers to those questions will help you decide if this was a one time incident or if he is a chronic liar.
I can understand your disappointment about who he is as a person. Keep in mind, in relationships it is easy to place our ideals on the other person, particularly early in the relationship. He did this in a way when he thought you would not accept him without the Bachelor's degree. You are doing this when you thought certain things about him. Adjusting those expectations is what is going to make your relationship work.
Also, if he continues to move forward, work on his goals, owning up to mistakes and generally treating you well, there is always room for letting him have a pass on this one mistake. Be sure you adjust your expectations of him to understand that he will make mistakes in your relationship as you will with him. As long as he does not try to deceive you again, then the relationship should work out fine.
Please let me know if you have any more questions. I am more than happy to help.