Please help me! I need advice. I'm a 14 year old boy being d by my mom's boyfriend & I can't tell her!?

I neep some advice from anyone here, other than talking to a teacher or friend because I don't want my mom to find out. I just don't know what to do. I'm a 14 year old boy who is being d by my mom's boyfriend. They have been dating for two years and he moved in with us last year. I thought Dave(not his real name) and I were getting along great and he seemed cool until four months ago when my mom went to work(she works evenings), Dave looked at me differently. Before he looked at me in a fatherly way but this time he looked at me in a very uncomfortable way, I can't even describe it. I never had any reason to think he'd hurt me in a ua| way. He has said plenty of times how I'm such a cute boy and must be a hit with the girls but I'm sure dads say that to their sons on occasion. Anyway, he grabed me and started dragging me into the dining room. When I resisted and asked what he was doing, he slapped me. He then threw me onto the floor and got on top of me. He ripped off my clothes and d me ly. I screamed from the pain and he slapped me again. I couldn't believe what was happening. I felt so betrayed and terrified. I was bleeding. Why did he suddenly go from being fatherly to a monster? When he finished raping me, he grabed my hair and threatened to hurt my mom if I tell anyone what happened. He just left me there on the floor crying. When mom came home the next morning she noticed my eye lids swelled up and that I was walking funny. Dave told her that he gave me a whipping for not minding him.(mom allows him to me when I misbehave so this was the perfect excuse for him). Him raping me has continued almost daily for four months now and I have learned to deal with the physical and emotional pain from it all but lately I have been bleeding from my rectum more than usual when he's finished raping me. I notice it on my underwear and especially when I take a poop. It's so sore there too. I have been hiding my bloody underwear but I'm so scared my mom will find out and I'm even more scared as to why I'm bleeding. Could I have a disease? I heard about diseases you can catch from having . I'm so scared. I can't go to a doctor or nurse without my mom finding out. I know this Dave guy will make good on his promise to hurt my mom because he's so violent. Like one other time when mom was getting ready to go to work, I asked her if I could spend the night at a friend's house(to try and get away from Dave) and Dave interupted before mom could answer and said "no,you can't. I told you you were being punished for not doing all your chores" so mom agreed with him. So I was terrified when mom left because I pissed Dave off for trying to get away from him. He then grabbed me by my hair and dragged me all the way upstairs into my bedroom, threw me on my stomache onto my bed, yanked down my pants and underwear and whipped me on my bare backside with his belt until there were plenty of red and purple welts. Then he d me more violently than he ever did before. I thought my life would end that night because I was so overcome by extreme pain. I just don't know what to do. Can someone tell me what the bleeding from my rectum might mean? And it's so sore too. I wince when I walk and sit down lately and mom has noticed but I just make up some excuse. Is it just because of him raping me or could I have a disease? Could I die? I'm so scared. I can't do anything where my mom might find out because she would be so upset and I'm scared that Dave will hurt her. If it's nothing serious but just normal bleeding and soreness from then I can put up with that but if someone thinks it could be a disease, then I need advice on what to do. PLEASE HELP!!!