I lost my first horse at 14 years old, so I can totally sympathize with your loss. In fact, I’m 27 now, and thinking about it makes me cry still.
I got him when I was 7 years old, and while he was my first horse, he wasn’t technically my first ever…I had a rotten mean pony from 5 years old to 7 years old, and when she bucked off a friend who broke her arm, she was sold.
Enter, best horse ever.
I put him down because he foundered in all 4, so badly that he was holding himself in a standing position by putting his head over the stall wall, and essentially, using his neck to hold himself off his feet.
It was THE.HARDEST.DAY. of my life…to this day. He was my first love, my best friend…and I had to make the call.
So, I totally get what you are going through. I have had many horses since, but none compares to him, and that’s fine, because he was so special, I can hold onto that for the rest of my life.
I kept his halter and leadrope, which to this day has never been used on another horse. It’s hanging in my new barn’s tack room, with a picture of me and him when I was 8 years old. A shrine like area, if you will. Also, we had him put down in April; the Christmas right before, I had gotten new brushes. They had only ever been used on him. I still have those, and they still smell like him, 13 years later. There are a few other things of his that I kept, and they are all in a very nice oak hand-made tack trunk (a small one, much too small to be of use in the barn) that my uncle made for me that Christmas after he passed. It’s in my bedroom, and contains a braid from his mane and tail (I couldn’t bring myself to send them in the mail for a bracelet - I would be devastated if they were lost), and the rest of his things.
It will take a while to grieve, and that is okay. Take all the time you need.
Thinking about what you’re going through brings back my memories like it was just yesterday. And especially so, because I’m at a point right now that I need to make this decision about my mare within the next week or so. Aside from the gelding I mentioned above, she is 2nd best for sure. Those good ones sure are irreplaceable, and they will leave a hole in your heart, ever over many years. That is what makes them special, and I’m thankful I had that with a horse.