Upper wisdom teeth very often are angled towards the cheek while erupting through the gums, and that can cause the troubles the OP is having. In most cases, the tooth turns downwards during the last phase of eruption, but the sore cheek can be pretty cumbersome.
My advice as an oral surgeon with a lot of maxillofacial surgery background: Get an ointment at the pharmacy, one that sticks to the mucous mebranes after application and releases its active ingredients in the course of several hours. It's called a dental adhesive ointment and, of course, it has nothing to do with a denture adhesive.
My suggestion is Solcoseryl. It's a tiny tube, only 5 grams, and costs about ten franks. Quite expensive, you'll say, but you just apply a quantity about as small as a coffee bean, so it lasts a long time.
Don't even try to rub it into the mucous membrane. The mucus layer prevents that. Just smear it onto the sore area with a swift movement of your finger tip and let it sit there. It will form a slimy layer that sort of sticks to the surface.
Do that three or four times a day. It will sooth the pain and assist healing. If that doesn't significantly help within, say, four or five days, see a dentist. If it helps, wait and see. If it occurs again, do the same procedure again. If you have to say, "What's 'nuff is 'nuff," see the dentist.
Pulling an upper wisdom tooth without complications costs you about 140 franks, basic examination included. If an x-ray picture is necessary, that will cost you another 20 franks or so, and if more than one injection is needed, that will be yet another 40 franks.
Wisdom tooth extractions can become more expensive when more surgery is involved, which is rare with upper wisdom teeth and even much rarer when they are already partly or fully erupted.
In my opinion, way too many wisdom teeth get extracted without real necessity, sometimes with the simple explanation, "It's a wisdom tooth, so let's remove it." Especially in the USA that seems to be a very wide spread philosophy; it's somewhat better in Switzerland. In most cases, Mother Nature sooner or later will take care of the problem.