Is it normal for me to be feeling this way?

Before I begin on my problem, I have to tell some background information. About a year and a half ago, a long time friend of mine (friends since the 3rd grade) had his mother pass away from cancer, and before she passed, she and my parents agreed that he would live with us since the rest of his family was out of state (this was all in the 10th grade). He has been living with me ever since, and we consider each other step-brothers. Also a year and a half ago, my mom had a work friend who wasn't home often because of work, and his oldest child was harmful to the 3 younger children (mainly the 2nd oldest). Because of this, my mom and her friend would often arrange for her 2nd oldest daughter to spend the night or weekend at our house. The 2nd youngest daughter was 14 at the time, and I was 15; and the daughter was not allowed to date boys until she was 16 years old. I am not great with approaching girls, so I have never really had any girlfriends, which is what made this issue so much harder for me to deal with. Because of my lack of skill and being too nervous at approaching girls, I have also never experienced Valentine's Day with a girl. I began dating the daughter secretly because we both felt strong affection for each other, and we kept it secret for about 3 months, and she would come over about every weekend and spend the night, which gave me and her a lot of time to spend together considering the fact it was a secret relationship. I consider her to be my first love, since it was my first (at least in my book) serious relationship. Nearing the end of January, the frequency of her coming to stay at my house lessened due to a lot of her own family issues, she began staying the night about once every other week, which sucked since we didn't get to see each other as much, but I felt that it was not a huge issue because I thought I loved her, and I thought she loved me. Two days before Valentine's Day, I flew out to see some family out of state, and while I was gone, my girlfriend spent the night at my house for that weekend while I was away. I was bummed out by this of course, but again, I thought it was a minor obstacle. They day before Valentine's Day however, she broke up with me (over text), and it crushed me. I was depressed for a few months (I still kind of am), I would hide in my room and spend as little time with people as possible. I tried talking things out with her, but found I got too emotional, and that I knew I would need a break of contact from her to completely heal; which is what I did, and I haven't talked to her since. The thing that hurt me the most however was that a month later, I found out that she had made out with my brother (who was dating another girl at the time), and she had also gone half-naked when they did this as well. This was difficult to cope with since I had just then found out that my first love, who I put all of my trust and heart into had done this to me, and that my long time friend turned step-brother had also done this to me. I felt very betrayed and avoided my brother a lot to avoid starting a conflict that I knew I was going to create if I was with him too long. He admitted they had only done this once, and then stopped doing it afterward because he felt terrible about doing this. My parents found out about me and her dating, and later about my brother and her, so she stopped coming to our house. It has been about a year since this has all happened, and while I still get depressed occasionally about this, I am mostly back to my former self, but very recently, I was told by a friend of my brother's girlfriend that my ex-girlfriend did more than just make out with him. I am not sure if this is true, because my brother told me a different story, but I'm not sure if I believe him. This has recently sparked my depression again, and no matter how hard I try not to think about it, I end up thinking about it. It's strange to me also how I only feel depressed when it reaches nighttime. During the day I'm upbeat and happy, but at night, I seem to get very depressed and "lock" myself away. Is it normal for me to be feeling so upset and depressed a year after my first serious girlfriend broke up with me and (to me at least) betrayed me? I also feel like I still have feelings for my ex, which I'm also not sure if that's true or not because my emotions are confusing me, and if I still do have feelings for my ex, is that normal? And if none of this is how I should be feeling a year after the break up, then why I am feeling this way?

Hi- I think what your'e feeling is normal. Betrayal teaches you that people may not be who you are lead to believe they are. It's a life lesson you will always remember. It's especially hurtful when both parties are close to you. Your brother minimized it by saying "it only happened once" Once is all it takes. Anybody would feel as you do. Change up your routine at night so you're busy and have less time to "dwell" "Time Heals All Wounds"