Hi Vee,
Finding your way out of the hole that is depression or the blues can be tough, especially if the outside conditions that are feeding them aren't changing.
But here are a few things I found helpful:
For starters, since the lack of the relationship is what seems to bring this on: Have you checked out Margaret McCraw's book "Tune into Love"? Here's the link at Amazon:
Amazon.com: Tune Into Love: Attract Romance through the Power of Vibrational Matching: Books
I really like it. Easy read, very encouraging. And using the LOA in a very hands-on way.
About LOA: I can see how sometimes it can be daunting and almost backfire when it's focused on too much. After all, it says what we think about, we attract, so when we think negative thoughts, it can make things even worse. We worry about what we worry about, and then we worry about the fact that we're worried about it, etc. Ouch!
The thing that helps ME a lot with this is Abraham's "Working your way up the emotional scale" exercises (the new books are almost all about those). The most detailed one is "The Amazing Power of Deliberate Intent", and on a less elaborate scale per exercise but broader range of issues, there's "The Astonishing Power of Emotions."
Also things like Bach Flower Remedies help over time, as well as EFT, going for walks in nature (or at least the park), oh, and chocolate ;-)
It sounds like you're already doing a lot of the right kinds of things, so maybe adding a few other tools, including the emotional scale exercises that work because they acknowledge that it's really not possible to go from depression to bliss instantly and work with that rather than against it, will help.
Good luck.