I agree with most of what Lylan states, but I do not think it is necessary to speculate what type of man he is (the "jumper" comment), as we do not know the real reasons behind his actions. He may in fact be doing that from women to women, but there are a myriad of possibilities as to why he does that. Some people have just experienced things in life that may require them to deal with stress by requiring space in the form of isolation, or traveling, and so on. If even his mother states that it has been a habit of is, I can't quite say it is as simple as jumping from women to women if he really does go off the charts to everybody. Either way, I think it would be unhealthy to speculate on this since it is negative in nature (without having any solution to it).
Instead, just focus on the fact that you are unhappy with the situation. This must be exceptionally hard on you given that this has been your first real experience with somebody, but it is imperative that you understand that this is not something you should settle for. The reason why divorce rates are so high nowadays is because the individuals themselves that partake in what was suppose to be a very serious matter, were too immature/incomplete for the commitment required. You should find yourself a man, no matter how hard it may be to stay single/uncertain, whose personality and existence in your life, you do not have to question, and never have to make a desperate post asking random people in a forum.
On a final note, I do not think he should be reprimanded for telling his sister a secret of yours. Everybody has failed to keep secrets and some point so this isn't something anybody can judge on since we know as a result that it isn't always black and white about whether or not some things should be kept. Family is also much stronger than friends or love interests, so I can't say he was in the wrong.