I know this subforum is meant to be for a healthy distraction, but I have no idea where else to put this.

A few years ago, my mom got a dog from her coworker, who entrusted the dog to us for a forever home. Within the three or so days that we had it, it quickly became mine, as I loved the little dog Riker and everyone else apparently hated him. He was just a little hyper, that's all, he wasn't bad, he didn't destroy furniture, and I was working on getting the cats used to him.

I went somewhere after a few days of having Riker, and when I came back he was gone and my family told me he ran away, which I believed for a year or so- that is, until my sister accidentally let it slip that she and my dad took Riker and drove him off miles away, and abandoned him in some random neighborhood.
I live in South Central TX, and there's a rampant problem with strays and missing dogs down here, so not a lot of dogs actually get saved. And when they did it it was the hottest part of summer, where it gets up to 110 degrees. So there is little chance that someone noticed him and took him to a shelter or kept him. He was small and unnoticeable.

Its been maybe a year and a half since I found out, and I still think about him a lot because I want a service dog, but I'm worried. Every time I think about him I cry. I know abandoning an animal counts as cruelty, but where I live you can't be fined for it, and I don't have intentions of getting the law involved.

The main reason why I posted this, was because every time I mention it I get upset, and my family brushes it off. I was talking about it with my mom, and she sighed and said to "let it go, it's been a few years already". How can I let it go?? He was an innocent little dog and my dad left him somewhere, all because they didn't like him. I can't forgive his cruelty, I get so so angry thinking about it.
I can't stop thinking about how much I grew to love him in those few days, and how much more i could have loved him and cared for him if my dad hadn't done that. How can I properly grieve for my little dog when something like this happened to him?