I am a chronic cluster headache sufferer too, nearly 30 years.
I will be completely frank with you, smoking flowers and mediocre hash won't do anything for your cluster headache if your diagnosis is correct, if it is helping then it is more than likely you suffer from a migraine type headache rather than cluster headache.
To hit the pain of a cluster headache you need to consume an oil that is in excess of 70% thc, have the right balance of CBD and CBN, and it has to be very clean, any impurities will exacerbate a cluster headache. I have tried lots of different extracts, oils and I've found that really only the strongest and cleanest will help with pain relief. If you can produce your own rosin for starters that works well. But again its the practicality of hitting a dab whilst suffering pain worst than childbirth!
Now you mentioned mushrooms, do your research as from my own personal experience I've managed to abort a cluster period for 12 months by using Psilocybe cubensis mushrooms I cultivated myself. I suffer from cyclical cluster headaches so know roughly when to take the mushrooms as preventative but as you know, cluster headaches don't come when you want them to and I got caught out 2 months earlier than expected this year.
The other significant relief I've found is breathing oxygen, if your doctor can prescribe it then get on to it fast, nothing works as good to relieve a headache than pure oxygen after a rosin dab.
Invest in some stealth and carrying on growing in Lithuania

, Netherlands is not the answer to your problems, trust me I looked at the same thing 10 years ago.
Good luck and peace!