Advice on recovering from multiple pet deaths?

This summer and fall have been rough on my family, myself especially. While working through a spay and neuter program for our local feral cats, we inadvertently became involved in kitten rescue to help the ones abandoned by their parents or sick. As most people who've raised young kittens knows, that's a pretty heartbreaking business. We lost half of the 8 total we took in. In the midst of all this early this summer, I also lost the last two of my old-girl Betta fish. A couple months ago, my one rabbit had a serious urinary tract infection. Being late on a Sunday, I took her to the emergency vet. They kept her in the back room too long while handling other serious cases brought in, and she died of a stress heart attack. Now just last week, I lost my second bunny to reasons unknown. She stopped eating last Thursday evening and, despite our efforts to help her, passed away overnight.

At this point, I'm debating whether or not I've sunken into literal depression. I feel like I'm some sort of horrible bad luck. So far as rabbits go, we still have 4 in the house, but they are my mother's and are bonded to and cared for by her. While I really miss having my bunnies (letting them out to run around was my stress relief after work) and have a brand-new cage I was all excited about when I finished it, I'm now terrified to get any new pets.

I know that there are probably people on here with somewhat similar experiences (particularly if anyone's raised livestock like sheep/goats and had to care for a round of babies that fell ill or something). What the heck do you do to get over it? I've debated volunteering at my local SPCA with their buns and such, but animals in shelters aren't always in the best condition just because of the situations they come out of. I think knowing some of the animals there will pass away or have to be put down would actually make me worse, especially because I might superstitiously blame myself if it was an animal I was helping with. I also would only be able to go Friday evenings or maybe Saturdays.

And please nothing about psychologists or anything like that! Besides the fact that I don't want something like that in general (I'm more of an animal-person than a person-person), I don't have the money for something like that. While I'm surviving just fine and can pay for myself and normal vet bills, I've lost a lot of money this year to veterinarians, a car accident, horse boarding suddenly hiking up costs, and other factors.

ABRIDGED VERSION: I've lost a lot of pets since June and am a wreck about it. Seeking advice on ways to slowly recover from the emotional trauma