Extremely stressful family/relationship problem please help :(?

Right, please dont judge me because we are not actually related but I have had a huge crush on my step brother for over a year. I just thought it was a crush and it would go away so I started seeing this guy at school I like and things were good however these feelings for my stepbrother still remained. When I last went down to my mums house (where my step brother is, I live with my dad so I don't live with him) my stepbrother admitted his feelings for me and we had a long chat which resulted in me confessing my feelings for him but still letting him know that i love my boyfriend. Recently things between me and my boyfriend haven't been so good and with this, things being difficult between my parents and my exams I've started showing signs of depression. I feel like I need to make a decision about which guy to choose and I feel like such a player saying that but I'm really not that type of girl, I'm 17 and the furthest I have gone is kissing. I love both if them and I know it's only a decision I can make however Im just so stuck right now and don't have anyone else to turn to except on yahoo answers. I know if I choose my step brother it may cause a few family problems however they are not serious. If i choose to continue seeing my current boyfriend of 7 months then I know things will continue to be unhappy but I'm uncertain about leaving him as I do love him. My boyfriend is the same age as my and my stepbrother is 22 (Age is not an issue). I don't know what to do who to turn to and I can't talk to my parents about this and my friends aren't of much help. Please help me, I'm extremely close to tipping over the edge :/