Twin Trouble

I (20m) am writing this to spill my guts hopefully it will help. Me and my twin sister (20f) have been close our whole lives. We were home schooled till high school. So we were always together. For the first couple of years in highschool were Hung out with the same people and took same classes. It wasn't till she met her first boyfriend. I didn't like him but everyone was saying I was being over protective. After they broke up we got close again. By then we had started getting into the neighbors garage fridge he had liquor. One night she was tipsy she admitted she missed her ex and started telling me about the first time they had sex. I have to admit was getting turned on but I helped her to bed. After highschool she had another boyfriend he seemed nice. Until he cheated on her. Last week she got a few messages from him and she thought he wanted to get back together. After they had sex she found out he had a kid and a gf. So she got upset. She found someone to get her a bottle. I drove her to her apartment. She didn't want to be alone so I stayed with her. I hid the bottle because she didn't need anymore. She spilled food on her cloths so I took her to her room. But I had to help her change. She actually ripped off her tshirt and bra. When I told her she had to put her breast away. She told me no. She told me she was proud of her boobs. I had never seen them. But because I feel safe talking anonymously I can say her breast were nice. But eventually I convinced her to put her shirt on. She took off her pants the shirt was just long enough to cover her vagina area. She wanted to watch a movie. So we did. At one point she asked me to rub her scalp. It would help with her headache. So she put her head on my lap and I started running my finger through her hair and massaging her scalp. She was on her phone and I saw her looking through pictures. I noticed that there were a few of her topless. I kept my cool but I couldn't help thinking about those pics . She started falling asleep so I took her phone and put it on the table. After a minute she was asleep. Her phone was still unlocked so I decided to search it. I found the pictures of her topless. I also found a few full body frontal shots. Her pubic hair had a Landing strip. In one picture it was shaved to look like a heart. I wanted to stop I know I shouldn't keep looking but I looked some more. I found a bit of her giving her ex a blowjob. I decided to send as many pictures and videos to myself as I could. I deleted the messages. My sister woke up because I had gotten hard and was poking her face. I pretend to be asleep. I felt her touch my hard on but it was fast and that's all that happened. But now I have these videos and pictures of my sister. I use fell bad using them wondering what it would be like to sleep with her. I am currently masterbating writing this out.