Hello ashleykaynee! Don't worry you are definitely not alone, especially in this forum! I would bet that many people will come along and offer their opinions and you will realize that you DO belong, especially in this group of people who have all felt what you are going through.
I thought I would offer up what happened to me when I went back to the States for a week at Thanksgiving this year, as I was feeling very homesick and depressed myself (if you look back at my posts from a few months ago, you will see I had the same sort of breakdown, so I definitely understand how you are feeling).
When I went back for that week, my hubby and I discussed in length that the trip could either make me feel more homesick or help (giving me a dose of what I missed to hold me over so to speak

). It turned out that I kind of had a revelation when I was there. I did absolutely LOVE seeing my closest friends and family and catching up with them and doing all the things I felt I had missed out on (like going to my brother's engagement party and my going to a game to cheer on my favorite football team). Those parts were wonderful! But I also realized I desperately missed my hubby and stepson (even though we had been apart for much longer periods of time, so it kind of surprised me how much missing them hit me). I missed certain things about the UK too, which also took me off guard cause I had gotten into such a funk that I hadn't been able to take stock of the things I love and appreciate about life here--I was only focusing on what I missed from the States or comparing things between the two countries.
Then funny things began to happen. I realized that while I adore my family, there are some things I am happy to be at a distance from. My father and I have a much better relationship from a distance, we can appreciate each other more and enjoy the best of each other. I also have a sister who is going through a lot of problems with alcoholism and I see how it is bringing down my family and sometimes I am grateful for the distance as it doesn't land on my doorstep every day in negative ways.
My best friend and my brother are the two people I miss the most. But I got to have some genuine laughs with them. I realized it is OK to feel torn between the two places! There are people and things I love in both! I shouldn't expect so much of myself to be able to forsake one for the other completely.
What I am trying to say is that my visit back gave me some perspective on the fact that I love my friends and family in the States, and I am always glad when I get a chance to see them, but I also realized there is no place in the world I would rather be than with my husband and stepson. And circumstances mean that that means living in the UK, so I am working on embracing that rather than fighting it. I think for us expats, sometimes the phrase "the grass is always greener" is very apt. While some transition very smoothly and are 100% on board with everything UK, I think many of us will always have our hearts in two places. Acceptance of that is key, in my opinion.
So I cannot say for sure what it will be like for you, but I thought I would share my experience so you realized you aren't alone in how you feel and so you can reflect on whether a trip back home would help you lift yourself out of the depression you feel at the moment.
Feel free to message me if you need to talk to someone!