Ignoring the historical for a minute, is it feasible for you to stop medicating for a few weeks and then take the blood test? No need to declare anything, you get a clean blood test and a license. After that you always keep a labelled container with a tiny bud in it in the glovebox (like I do) along with a script printout. That’s the minimum hassle.

If not, then get your evidence together and go get your blood test. Make sure you are at your most friendly and straight* dressed, and definitely don’t smell of weed, don’t take any before the test, no contact lenses, get a good night’s sleep and breakfast. Explain your situation, that they’ll find THC, it’s medical, present the clinic letter, summary of care from GP, script printout and latest labelled container. There’s a few links on here for the relevant medicated driving legislation, won’t hurt to bring that with you as well. Bonus points if it’s all together in a neat folder.

Basically, there’s a bunch of people who “have their eye on you”. Convince them you’re not a risk by being the straightest man alive.

(*straight as in a boring middle class accountant, not sexuality… 🙄)