About "choosing to be alone," I guess there are two general types of being alone: Choosing deliberately, or just having it happen to us.
I suspect that the second is by far the more likely situation for most people. I didn't choose to have my husband grow progressively more ill and die; we had a good life together. Interestingly, I had never lived on my own. I got married right after I graduated from college, so I basically went straight from my parents' home to our home as a married couple. Followed by 3 children, and eventually, 2 of our parents living with us in their old age.
When it was obvious that I would not have DH much longer, I wondered what it would be like living alone. Our children were all grown and out of the house by then. I found that, although I missed him, there were advantages to being on my own. I like the independence, living by my own choices about everything, feeling, maybe for the first time in my life, like a complete grownup. I had to learn to deal with a lot of household stuff that he always did (car maintenance, for instance) and found that, like nearly everyone else, I could learn to do it all. I even went on a cruise by myself, and to my surprise, it worked out fine. (Wouldn't go on a cruise now, but that's another story).
So, although this wasn't my "choice," I've found strengths that I didn't know I had. Holly, you sound like a bright, strong person, and will find your own level of independence. Communicating with other people, such as on this forum and in other venues (online, in person, whatever) is a big help.