"Suffocating and want to die" is not good! I would tell your doctor how low your feelings go and for how long. Consider anti-depressents. Are you sleeping ok (not counting passed-out drunk sleep). Because sleep deprived people can not handle emotions well and might need sleep aids for awhile to get back on track.
I would also tell someone IRL about the drinking (counselor, doctor, pastor, friend, family). My mil used drinking to ignore and forget fil's behavior, and it really messed up their kids.
As for his "reason", he needs to dig deeper. Why wasn't he ready for kids? He hadn't grown up? He was immature and irresponsible? Why did he agree to kids anyway? How is he different now and why?
((Rya)). Bottom line is don't battle these slumps with alcohol or alone!