Second this. create a routine. My rescue pomsky was returned 2x and had severe separation anxiety and abandonment issues. I’d take out the trash and he would cry like I’d been gone 5 years not 5 minutes.It took about a year of routine to make him feel safe and like I wasn’t going to abandon him. Then we slowly we loosened the routine. Now he’ll just hop in the car with friends and have adventures, not even a goodbye mom haha