Medical grade cbd oil is not yet legal in UK. Progress is slowly happening as public demand rises.
The problem with marijuana is that it was not legalised 40 years ago when it was a ''natural'' product. The tobacco and alcohol industries have long held influence over successive governments. It is now mostly bred for the THC content and is far too strong, leading to a risk of psychosis. While the THC delivers the high it also causes paranoia. In old style marijuana it was balanced by the CBD content. Until the pandemic the ''safest'' but illegal source was imported resin, taken orally.
Seeds are available online for high CBD content plants if the cultivation is legal where you live. Do not smoke or vape anything.

Fortunately the CBD is also found in hemp ( Cannabis Sativa), though in lesser quantity.
I use 30% full spectrum hemp oil, carried in hemp seed oil, as an aid to relaxation.
I'm pleased with the long term benefit. It is a good source of Omega 3, 6, and 9.

Many herbs are linked to lung health, but it tends to be a personal thing. I don't get on with eucalyptus, or turmeric for example. I do get on with lavender and also blue chamomile as aromas. Liquorice is a good expectorant but too much may be counter productive.
I make up a daily dose of ginseng, horehound, ocha root, and mullein extracts, none of which have any known contra-indications to any medicines I use. This should always be checked.

It all sounds like a lot of bother, and expensive, but it takes approx. 1 minute/day and costs £1:00 / day, for the 7 herbal extracts mentioned above. They have been chosen to give an holistic approach and cover airways, immune system, fatigue and anxiety, and are used to supplement a good diet, high in beta-carotene antioxidants and low in refined sugar and starches.

We must bear in mind that emphysema is an irreversible physical degradation of the lung tissue, but if we can work on a ''reset'' of the immune response and on the inflammation caused, there is benefit to be found for both asthma and bronchitis.

😊🍀

Not script Marijuana. But cbd oil without a prescription on my end. But I love the cbd oil from Green Roads in Florida.i have no affiliation so I am not giving them an advert here. I wish I could get my hands on some Marijuana so I could test it myself. The cbd oil works fairly well orally or in with non nicotine e-cig oil. Kinda scared to keep that up even tho my breathing is easier & haven't got bubbles blowing in my lungs when using it. My lungs lied to me before, so I get kinda suspicious when they say "Hey this is helping." Lol

I agree with what you said that I have personal knowledge of. But I do take the Turmeric as it helps the inflammation in my lungs & my arthritis. Not all things work on everyone. But you are so right about the Lavender, mullein, & Ginger. Those ate good. I try to get some every day. Hot lemon Juice also helps me. I have never heard of blue camomile, but I will.look for it. Don't know if they even sell it here. It may be something unique to only your area. I also use Thyme. My son makes me a pot of tea with a lot the herbs mixed just before bed. During the day, I do the lemon juice & I take the Tumeric 2 x a day. I cannot buy Marijuana without a prescription here in my state. I could drive all the way to Colorado & get some. But if I were to get caught here with it in my possession I would be on my way to Jail in a heartbeat. In Colorado, I could smoke it while talking with a cop & I would be fine, as long as I didnt get caught driving with it in my system. Weird with so many laws in the same country. But we are a country made up of tinier countries we call states. Usually they work in Unison, but the last 12 years they have not done that.
Have a great day. Breathe well. Stay safe!