How can I overcome the death of my kitten? I can't live without him.?

my kitten of 2 months was diagnosed with kidney failure and on top of that, the vet suspected a dry FIP. which is a disease that has no cure and wouldn't have let my kitten live more than 2 months since it started. i had already taken him to the vet before for an upper respiratory infection and he nearly died but he survived. i was so happy knowing that he was still alive. then he got sick again and that's when they gave me those diagnosis and we had to euthanize him. i can't bear it. i can't stand remembering how i handed the vet my kitten knowing they would kill him. i can't stand remembering how my kitten was holding tight to me even when he could barely move. i can't stand all the memories i have of him, waking up to his face, watching him play around, falling asleep next to me, every single thing he ever did. i still have to pay over $700 for all the treatment, and he's not even here with me anymore. i would do ANYTHING to be able to hold him. the worst part is that any picture or memory of him triggers me to feel like this. like i don't want to live anymore. i don't want to live another day without him. i miss him so much, it's not fair that he had to die. i want him next to me. here. but that's NEVER going to happen, and that's what hurts the most. i miss him so much, i just want to be where he is...i can't stop crying...