I really really second esloco's advice. You need to desensitize your dog to being alone in his crate. If he can't even get to 10 minutes, start with 30 seconds, or a minute and gradually increase the longer he stays calm. This can be done in the evenings and weekends - do a crate session for however long he is okay for, let him out, play with him a bit, then do another crate/alone session.

Also look into meds if you're that desperate. Our rescue dog had separation anxiety, would bark, whine, excessively drool, ignore treats, tear up his bed, pull at the crate door, etc. We got him on some anti anxiety meds and I'm currently watching him curled up asleep in his crate while we're at work right now.

Meds are to be used in conjunction with training though, so if you go that route you need to continue to train and desensitize him to be alone. The goal is to eventually get them off the meds if possible.