I was having one of these days last week. I'm sorry you are feeling so down.

For me the worst part is that the lows are so low and the highs are, well not *that* high but high enough that the reality of every failed cycle crushes me. The roller coaster is exhausting. This cycle I started feeling anxiety the week leading up to ovulation because I felt like we were out before we even got started. I'm angry, sad, and lonely with a few days of optimism peppered in - I also don't recognize myself some days. Yesterday I had to stop myself from getting mad at a friend who called and just asked how we were doing because I thought she was prying about TTC. I could kick myself for sharing that we were TTC with too many people.
I don't have any great advice, but also think the support group route may be very helpful. I just try to keep myself busy with things I enjoy like reading or running, although there are many days where nothing really helps. Sigh.