Ask your surgery if they use the Patient Access service - they should be able to give you a number, consisting of the surgery reference number and your own personal reference number, and then you can order on line. You still have to go and collect the prescription though, and our surgery asks for 3 days from request to collection - but you could order several days before you need them and then pick them up at your leisure. Also, there's a space for comments, so if you have holiday coming up you can order two months worth.
Equally, you could just phone your request through to the surgery.
Good luck