Today, I watched my horse fight for his life to stand up from laying down. I sat/stood by his side the whole time we were trying to get him to stand up but he was so tired from the fight.
He was an old boy, his last 10 minutes were him kicking his legs to get up. He would stop again, I would scratch his head again making sure he was calm. (We were waiting for the tractor to come help stand him up while this happened). The vet went to give him steroids to give him a boost, but he starts checking his heart then suddenly quickly checks how responsive he is being. He died right by my side and I broke. I couldn’t stop crying and even now I’m on and off crying. 

I’m really hurting right now and my emotions are getting uncontrollable and some thoughts have come to my head (dark ones).

Anyway I want to catch myself early before I really brake. Any tips on how to deal with grief? I’m desperate.