Don't waste your time pleasing with pharmacists, it would be highly unethical & more than their jobs worth to give out unprescribed medicines.
As a last ditch attempt you could go to a private gp and ask them to write a private prescription. They may well do it if you can supply evidence from Irish gp. Thinking of placed like Medicentre in major London train stations, or look on Internet for any private gp in your area.
You'd need to be booking an emergency appointment now & also ringing pharmacies to find out who has the unusual prescription in stock...
I know how stressful this is, having been in the same situation, with gp receptionist having fucked up repeat prescription all week, then being deliberately obstructive and refusing to inform the gp of what had happened (out of spite as I made her look bad). I needed venlaflaxine, amiltriptaline, plus high doses of fentanyl and morphine, so major physical dependencies and danger of very nasty side effects (like, err, death), as well as risk to psychological health.
The receptionist had 'forgotten' to give the repeat prescription request to the gp, then when she did that, days later, she then lost' them, and then to add insult to injury, she then refused to give out the replacement prescriptions issued on the grounds that I'd have too many controlled substances, if added onto the first set of prescriptions - the ones she lost somewhere between the doctors office and the receptionist desk.
I finally managed to get through to a doctor at 6pm on Friday, who was horrified as she'd even had a couple of free appointments that afternoon, so had been available at the very time the receptionist was blocking me from getting medical help! The gp actually faxed a local pharmacy my prescription herself, as she didn't trust the receptionists to do it. The pharmacy had ordered in the CD and stayed open 20mins later, otherwise it would have been Monday or Tues before I could have got them as they don't keep CD on the premises. I still didn't get the venlaflaxine (can't remember why in the tangled mess of events!), so went cold turkey off it & didn't go back on. Not good.
It's awful someone else having your life in their hands and not behaving in a responsible way. This was last year yet the sense of panic and dread is still there as of it were yesterday. Shudder.
Good luck 