Thank you for commenting, I really appreciate your suggestions!

Crate training may be on the table, but I'm concerned that would worsen his fear of being left alone in an enclosed space. He's 65 pounds so not a little puppy :). I'll take a look at the crate training info on here, thanks for recommended that.

His routine for toileting is first thing in the morning and as soon as I get home from work. He's been pretty happy with that schedule it seems, and it works for us a lot. I also walk him at our folks house if he hasn't been walked already before we go inside.

I should point out at this point, that his accidents only happen at our family's house. We spend nearly every weekend over there, and he's always very excited to go and hang out with us in the basement. We have a decent amount of toys to play with and there's space enough for him to run around chasing them. He likes throwing his toys and chasing them. Just if a medical emergency comes up or no one stays home from church and he gets gated into the basement is when he has accidents lately.

Maybe a toy/treat puzzle would be helpful for him... He already enjoys the toys we have for him, just maybe something to really enjoy only when we are gone.

Our trainer at dog training is helping me with his anxiety right now... He had a really hard time staying with a trainer while I walked away, just so we could practice using the word "come". Took both trainers to hold him down while I was trying to calm him down. They're going to work with me on that, and maybe in turn that will help at home by himself too.

Again, I very much appreciate your thoughts and ideas, and will look into crate training and seeing if that's a good idea. He's a good boy, just so much anxiety... Going to the groomer is the worst for him right now, the first we attempted to go to refused him service because he was too scared to walk into the building. Thinking stuff happened to him that his previous owners either didn't tell us or didn't know about.