Please I need help with an important decision....What would u do?

Ok...So Ive been havin differences with my husband of 4 yrs....since bout an year ago.Most probably cause of our age difference...hes 33 and im 22.I made it clear 2 him when were just datin...that I was still pretty young and that even though I was gettin married with him I wanted 2 go to college and go out and have fun with him...like a normal person of my age..but I was willin 2 give the best of me as a wife 2. The begginin of the marriage everythin was fine...we were such a fun couple...but on the third year of our marriage he was startin 2 get careless bout things between us...he didnt wanna go out much or help me with the responsablities and I tried gettin help...we went to couples therapy...and he was thinkin that the Dr. was takin my side...he just recommend us to get separated...but it wasnt so easy...because when we got married we moved 2 puerto rico and all my family stays at FL so I didnt have anywhere 2 go and i couldnt just leave 2 FL and lose my job and miss my scholarship.So we tried and things havent change and hes just been pushin me away with the lack of interest in our marriage.The thing is that I still think I love him...but im not happy at all...I feel lonely here in a place that I dont even have my family close...So I just wanna leave with my family and start all over...I know is not a good time but...Ive been talkin 2 this guy I really like...he lives in the states not here in PR...so I havent been unfaithful 2 my huband...but i really would like 2 get 2 know him...I know I shouldnt be gettin off one relationship and get 2 another but...maybe it could mean a second chance later on.But I have so many things 2 worry about....like student loan I dont know if i would be able 2 continue in another school in US and my husband's mom has cancer and he might loose her soon and i just dont wanna see him goin thru that alone.What should I do? Should I just forget about everything and put my happiness first...so I dont miss things in life or Should I sacrifice my happiness 4 my husband thats not a bad person but doesnt make me happy? Plz Help!