Hope this doesn't get buried. I'm straight, but I had a somewhat similar situation to what you are in right now. I dated a girl my freshman year of college until the end of my sophomore year, a little over a year but around the same time frame to what you and Jack had. That year was the best year of my life. I thought I had loved before, but this put all other love to to shame. We had our problems like everyone else does; she was religious where I wasn't, she was motivated and striving for her future, and I was more focused on having fun, she thought ahead while I thought in the present. We broke up because we were "in different stages of our lives" which was probably true, but I didn't take it lightly. I went out and tried to drink her off my mind a lot, and thought that by getting her out of my life was the best thing to do at the time. But you always think of them, they never go away. About a year after we ended things, she died in a fairly heavily publicized car accident, along with her other friends. A tragedy it was called. While that was hard enough, I (rightfully) received a small amount of compassion because she was dating someone else at the time. And he was everywhere, the news, the family's house, the front of the casket. While I had to watch from the back. He deserved all the attention, no doubt in my mind, I wouldn't even have known how to react. I reached out to help him the best I could, and I may have helped, and I hoped I did. It sounds so selfish, but I wanted that attention as well. I sat by silently on the side, unacknowledged by most, while he got the help. I can't comprehend being totally alone because of your situation, but I understand the silent mourning. The nightmares are real, I've had my fair share of them, her being there talking and then gone right when I wake up. On getting through with this, the first month is the hardest. They seem to haunt you, always on your mind, seeing their likeness in everything, just a lot of thinking about them. After that your routine kicks back in and the business of life gets in the way of thinking: the thoughts of them get drowned out like a singer in a busy train station. You still think of them and see them when you do certain things or say certain words. Everything gets better with time, it sounds cliche, but it is the damned truth. You won't ever be normal again though. Love is giving part of your heart to someone else, and when they leave they take all that was theirs and more. And while all gets better with time, it can only go so far. You will hurt longer than you think, but don't hold on to the pain too long. As time goes on you appreciate what you had rather than being bitter that it is gone. Once you start to appreciate the love you both had, rather than being angry and sad that it is no longer there, is when there's an end to it. Relationships are always temporary but love is forever.
It is terrible you can't talk to anyone in person about this, but send me a message if there is anything I can do to help. I hope this helped you somehow.