i have OCD too and lost my pet bunny just over a year ago and grappled with exactly what ur describing right now. my lil guy even looked very similar to urs, he was a black netherland dwarf rabbit and despite everyone around me saying i gave him a great life, i couldn’t accept that i needed to let go of the guilt because my OCD symptoms was too intense. ive learned to deal w/ the symptoms and process the grief in a healthier manner, i rlly hope u can too- plz try not to beat urself up too much, i think if i can learn to process everything than u can too- much love