Good morning- anxiety is something that takes time, patience and in my opinion routine. Routine definitely helps. When your dog learns that they can expect “x,y,z” at certain times, and can depend on that routine, it builds trust. There are also other things like leaving a radio on low while you’re gone, walks/exercise to get them good and relaxed before you go, chew toys and toys you can hide a treat like peanut butter in for them to work on while you’re out…. I will also say that making walks a priority part of your daily routine helps a ton. For both of you- it helps with strengthening your bond- in turn helping them trust you more, as well as being physically tired. Training and repetition (even the most basic) is mental work and also helps keep their mind tired. A tired dog is a better behaved dog. There are lots and lots of tricks and tools. Lastly, I would check in with your vet and make sure it is not something that is more serious and needs medical attention. It is definitely something that you can work with and potentially overcome. One of our shepherds had terrible separation anxiety when we first rescued him- chewed EVERYTHING. It took time, but he is well adjusted and one now. Don’t lose hope????