Your "season" sounds familiar to me, but it's only April. A few things:
1. 15 hours is a LOT. I can't train that much without burning out completely.
2. 4 hours is still a decent amount of time. Are you doing 4 hours in one day or 6 days of 40 minutes each? If it's the latter, you'll be fine. Focus on intense days at least 3-4 days a week.
3. No matter what other people tell you, sometimes life does take it's toll on cycling. You can take back some of it, but it's very hard on you and your family/friends. So although I've done rides from 2-4 AM in order to get around work, I know you can't do this week after week. But one or two rides a quarter like that can actually help save that same quarter. You also need to rest and recover, not just from cycling, but from life. An 18 hour workday doesn't mean you have 6 hours to train.
4. There's always next year. I told myself that for five years.
good luck,
cdr