You would not be considered eligible for this drug with the symptoms you describe in many countries including the UK. In addition the drug is only given for a specific period not continually. You will in any case need to declare the drug at renewal / initial even if you have discontinued it and of course if you already have any medical your medical is invalid until you declare it and get specific feedback from your AME. I suspect they will ask questions and it may not be easy
Sorry not be have better news