I'm so sorry to hear you're feeling so down, although it's totally understandable and normal. I'm sorry this has been so hard for you, and that things are so unclear about what the problem is, if there is one. I agree with Violet, it's too hard to tackle new research and ideas when we're feeling so down, there's just not enough energy.
Can you think of anything you could do to put even the tiniest little smile on your face, something maybe that's fallen by the wayside with IF? take a bike ride, sit and watch birds, see a movie, go to a concert, go for a picnic, sit near a pond and put your feet in the water, etc., or whatever you enjoy that might make life feel worthwhile, even for a little while. Just the littlest thing can sometimes make a shift. Years ago, when I was in a very dark place with my DH's inability to commit to me and I had taken just about all I could bear of feeling jerked around by him and hating my job and hating my life and feeling I was never going to get married and have someone to share life with, I sometimes used to take a walk and not let myself go home until I'd noticed five beautiful things. I couldn't "decide" they were beautiful; they had to just sort of "strike me" as beautiful, things as simple as the way a tree was blowing in the wind, or two people laughing together, or seeing a funny dog, or the way a warm breeze felt on my skin. Sometimes I was so down that it took me a long time to notice 5 things, but I always did in the end. It really helped me remember that life has good in it, even if my particular life really sucked at the time.
I hope that you get some rest and some exercise (not to lose weight or any other "shoulds," but to get some endorphins released into your system) and when the time is right you'll start researching whatever feels right to you.
In the meantime, I'm thinking about you and sending you love and healing thoughts.