If you suspect your razor isn't sharp enough it probably isn't. You are in the UK I see. There's a very good bloke there, Neil Miller, who's forgotten more about razors than most of us know about them. I'm not sure of his time-availability but you could try contacting him about honing your blade. It would be one less variable to worry about.

Do you know if you have sensitive skin? Some creams and soaps set mine off on occasion and the fragrance in some aftershaves/balms do the same. For me it seems to be related to weather conditions (spring is probably the worst) as well. I've found the Truefitt and Hill Ultimate Comfort is good, as is the Martin De Candre Sans Parfum. Normal old witchhazel as an aftershave works well for me too.

Anyway, sensitive skin might not be a thing for you, but you are definitely irritating it. I'd see if you cannot get that razor pro-honed by Neil and see if that helps.

Good luck,

James.