Help having issues with my bulldog!!!

Recently having issues with my male old english bulldog any suggestions might help.

I have had my bulldog for the last 6 years, we was purchased when he was a puppy. I have another dog also and have had her being a jack russel for 8 years. My grandmother lived with me for the last 8 years, helping care for my dogs, which really turned into her babies. 6 months ago she recently passed away leaving my dogs broken heart and lonely. she was with them 24/7. Since then my bulldog has been peeing in my house a couple times a week. i do have a doggie door with fenced in yard so there should be no reason for this. He has had no accidents in house since he was a puppy. Also he is starting to get very aggressive towards my jack russel. jealous and treats being an issue. what can i do to stop the maddness??? I dont have the heart to get rid of him, he meant so much to my grandmother. he was actually the one that was with her during her last moments. HELP

Has he been to the vet to rule out any medical issues? That should be first, as it could be an UTI that he cannot control, and that discomfort could also be affecting his mood ...