First of all, don't give up. I know everyone says this, but it's genuinely going to get better. Trust me on that. Second of all, your sexuality is your choice, but it will be better for you to figure out what exactly it is (straight, bi, gay, etc.) first before you involve yourself with anyone else if you plan on doing so in the future. It will prevent any confusion that could arise in a situation, and make sure your future person is 100% aware of their sexuality as well. Third of all, sometimes the best love is to simply let go. Another cliche, but it is completely true. You don't have to protect anyone, but you do have to communicate with them. Look at the issue, and accept that sometimes there is no solution to it. Being in love is a confusing thing and sometimes it's better to avoid it until you realize why you want to love someone. Yes, ask yourself, "Why?" Trust me on that one too. Fourth, I say this because I have had the same thoughts as, "I never want to be with anyone again, I'd rather die alone." And I had a huge fear that I would die alone because I felt unfit for human relationships. But sometimes when you force it on someone, and when you force yourself to love for someone else, it won't work out. It's not genuine. I suggest to take a break from dating, or just talk to person A and B, and either let them live on their own paths, without you there, or figure out a way to just talk maybe once a week. Don't try fixing either of the situations, once you feel the way you do, it will confuse you for the rest of the relationship you keep with Person A and B. Don't lead people on and don't make the same mistakes twice.

I've hurt and been hurt similar to the way you have, and I contemplate deleting this account not because I want to completely drop everything and every memory of the past, but because I don't live for other people anymore. I don't love because of selfish reasons or because of manipulations. Sometimes you don't realize it, but the people who you hurt, will hurt you the most. Once there is an unforgettable pain between two people, it is best to let the fire dwindle rather than keeping it fueled with more.

Remember that your life is your life, and you are the most important person in your life. Take control of what you can and don't worry about what you can't. You will die alone even if someone is there holding your hand while your body decays. I really hope this helps somehow. Good luck with everything.