Your experience with your GP & the Portuguese pharmacist sounds excellent.
I've managed to have shingles twice (I was surprised the second time, but apparently it isn't as unusual as I thought). Both times, the worst of the pain didn't last very long. A couple of weeks, with occasional episodes for a bit longer.
I was told by doctors both times that the earlier you start treatment the less pain & the quicker the recovery, which makes sense. I caught it early both times: identified by my mother the ex-nurse first time with "Get thee to a doctor - now", & the second time I recognised it myself (one of those things that's hard to forget), & got it confirmed by a doctor at the local weekend drop-in centre*, who sent me straight to the local hospital to collect drugs to keep me going until pharmacies re-opened next day, phoning to say I was on my way. This was a Sunday evening. I was impressed.
Looks as if you caught it pretty fast, which is good. The initial improvement (& drying up of nasty little blisters) was very fast. The pain was mostly over in 10 days-two weeks or so, & I got twinges (some of them rather painful: cue sharp intake of breath from stabbing pain) occasionally for two-three weeks after that IIRC, but those were infrequent. The itching was a bloody nuisance, though.
*I said "I think I have shingles. I have (description) along this line here (indicated). It looks & feels like when I had it before." He said "Show me," I did. He took one look & said "Yes, that's shingles".