Grieving

I lost my grandad in April and we have just buried him in late May. I've had a really hard time coming to terms with it all. I have a lot of regrets which fills my mind in a daily basis. I was always at work and couldn't see him as much as I wanted and me as my nan didn't really get on so I never wanted to go round. Now grandads gone I miss him so much and I don't even know where to start to begin to move on. I visit him regularly at the cemetery (none of my family go which is fine as it's their wishes and choice) I was really close to him growing up. I was able to say my goodbyes to him and even was there when he died (not in the room as he passed when all of my family were out of the room) I can't seem to get his face out of my head when he had passed. Has anyone got any advice? I'm just really down and missing him a lot😔😔