I do not give advice ever.
Get a life. Hire a electronic drummer.
No, really, tell your drummer you think he needs some time off to decide what is important to him (whether personal issues or not). Invite him to hear the new drummer (who can not be trusted because he is young and probably only wants some money then off they go or so) and that your old drummer has been with the band and you know he has done better in the Past.
When both drummers do not do anything or show up, have the electronic drummer, it is better than nothing, and it keeps the beat.