Assume the shyness question was aimed at someone else ! Find it odd this shyness happy to be starkers in front of a stranger within a few minutes but to shy to buy condoms.
My advice, just do a complete reverse of it. Go to boots, get about 5 boxes of 10 of the things, and three tubs of lubricant and one of those swoon vibrators. Find the prettiest 20 year old cashier in the store and make sure you go to her.
At your time walk over and dump them all onto the counter in one go and just say to her "I've got a big date this weekend".
Result, shyness goes, and fit girl behind checkout thinks you are Don Juan and will remember you everytime you come back to shop there.