Oh, that's awful for you.
First of all, you need to have any serious causes eliminated (as you're now unsafe to drive). Call 111 and if it feels as though it could be described as a thunderclap or as suddenly as if you'd just been smacked around the face with a baseball bat, or if there is any sign of your face drooping or becoming clumsy/numb/weak, tell 111 this - they might advise you to go to hospital or see an out of hours practitioner as it may be necessary to urgently check your blood pressure, for example. But you won't know unless you contact them. If they are happy for you to wait until Monday to make a GP appointment, you'll still need to tell the GP reception staff why you need the appointment, as it'll make it more likely that you'll get one sooner.
In the meantime and if it is established that it's not anything urgently needing attention, have you tried using a gel icepack at all? You keep them in the freezer and when the pain hits, you grab it, wrap it in a teatowel and pretty much faceplant into it with all the lights off. They don't work for everybody, but if they do, they make bloodvessels contact, which can reduce the pain. A bag of peas in a teatowel is a reasonable short term substitute - use a marker pen so that you don't try and eat them after they've been defrosted and refrozen several times.
If they help, you can also buy instant chill packs for when you are out - with those, you pop the inner sections, the chemicals mix and this creates cold through an endothermic reaction, which could give you enough time to get home.
Some people find relief from using 4Head/menthol on their forehead. Don't let it get onto your eyebrows or above your cheekbones as it'll make your eyes stream for hours don't ask how I know that.
However, did the optician check the pressure in your eyes? If not, I'd really suggest you go to another one this weekend if 111 are happy for you to wait.
It could also be sinus related, especially if the dip just below the middle of your eyebrow or over your cheekbone is tender to pressure - if that's the case, Pseudoephedrine/the Sudafed only available from the pharmacist, not on the shelves, could reduce the pain - the most painful thing I have ever experienced in my life, literally wishing I would die, turned out to be sinusitis. The second time my eyes hurt similar to yours was due to a nasty flu.
In short, there could be any number of causes, some which would need to be excluded. So call 111 first.