Hello Jack,
I'm about your age, and have a cannabis problem as well. With that being said, I've been able to accumulate some significant clean time from it.
I don't think anyone with a drug/drink problem is thrilled with idea of not using their substance of choice ever again at first. It's the type of idea that becomes more appealing as time away from mind altering substances passes. It's simple brain chemistry.
I also had significant marijuana withdrawals. I've detoxed multiple times, and never want to go through that hell again. Sweating, insomnia, no appetite, horrible depression and anxiety. There were also times where I felt like my brain was just in pain. My best remedies for dealing with them in the moment were long showers, going on long sweaty runs (my last detox occurred in the middle of summer) relaxing sound therapy, whole foods, a couple herbal supplements that I did some research on, psychological support from counselors, and social support from friends and family. Whatever you do though, DO NOT drink alcohol as a way of numbing out your symptoms. You'll feel like death the next day, hinder your brain's ability to heal, and perpetuate the overall problem.
At the end of the day, the only way any of this misery you're experiencing is if you don't smoke again. Take it a day at a time. Hell, take it an hour or a minute at a time if you have to. Wishing you well.