My little guy has been use to being with my partner, me or family ALL the time. We had some family stuff going on and everyone was home and not working. She is now close to 5 months and we are all going back to work etc. He is great with going outside to the washroom, sit and paw commands but barks if you leave to go to the washroom for 5 mins. I have anxiety as it is and I'm going to be starting back part time=I'm the primary caregiver (which I'm excited about).... But I am worried about leaving him, however I have Appointments, commitments, work and hobbies

not sure how to help with the barking. He also barks at all ppl and dogs walking bye. I've never had a dog before and lay hog my partner has and is amazing with animals and loves them...this little guy is so attached to him b/c he's a suck for the pup BIG TIME. He has slept on the hard floor downstairs for months just because he worries and loves him. I logically know this isn't healthy but prior to now I was dealing with a lot and didn't even feel I voice my own opinion.
Any suggestions?