Thoughts on considering rehoming?

I have reached a point I never considered being at with a dog; rehoming. I would love to hear others thoughts given the context I am about to provide.

Context: I had to put my 7 month old (30wk) Rottweiler puppy down after he began experiencing severe degenerative neurological symptoms. Multiple vets were consulted before ultimately making the deciding to put my sweet baby boy to rest. (He had NAD). I put him down 11.18.25 and by 11.19.25 my family was sending my links to puppy rottie mixes at shelters and highly encouraging me to get one so that Saturday 11.22.25 we went to see one (I said yes because tbh I didn’t know what I needed and trusted my loved ones to help guiding me through this hardship, as I currently could not even return home due to saddness of the reminders of my baby) my mother ended up paying for him. I kept him two days with me and discovered it made my grief much much worse so they took him in and were going to hold onto him and help train him till I was ready…..until 11.28.25 when my grandparents dropped off their dog since they would be going on a cruise. So they felt it was too many dogs (their 2, the new adoptee & my grandparents dog) and I had to take one untik my grandparents returned. So I took my newly adopted guy home 11.30.25 and immediately learned he’s EXTREMELY food aggressive, short warning window before snarling and grabbing at me. I was legitimately concerned for my safety and I’ve had reactive dogs, though all I had since they were 8wks old and was able to nip it relatively quickly to the point they were not harmful to others human/animal……now today 12.1.25 I gave my little guy a different toy and he began growling when I got near, would snarly and grab at me once more. In both instances I have been unable to successfully trade, to help him give it up. I have a cat who I LOVE dearly and LOVES dogs. So I am greatly concerned for my cat’s safety, food is one thing but resource guarding even toys seems riskier especially since I can more readily navigate aggression toward humans but not other animals. From what I’ve read they say to have toys removed/ monitored but that does not seem fair to him at all to have no toys when I work or am busy, he’s just a baby 5 months old but already 55lbs. I feel guilty rehoming him as I made a commitment to this pup, though I also feel over my skis as a currently single woman who is still grieving her ‘Ferdinand’ of a boy.

Note: The pup in question is a rott mix, I assume with pittie. He was found and brought in because he was following a random person in Lynnwood, CA (An area notorious for dog fighting)…..pup is very afraid of the dark, does not like his collar touched, resource guards food & toys…I assume from trauma. He is extremely loving and cuddly minus his resource guarding. The collar & dark are not areas of concern.

2note: did not receive my sweet baby boy’s remains until 11.26.25 as well if that means anything