Although one can experience an oral allergy to fruit, it sounds to me as if you have had a reemergence of the cold sore.
A cluster of blisters is more common with cold sores than with an oral allergy.
I have the same reaction to fruit as you do. I wouldn't say its cold sore related but I can see why someone would think its a cold sore. Everytime I eat raw fruit, the roof of my mouth starts to itch and it feels like a rash. Then I get the same reaction with the tiny blisters on my lips and my lips swell. It will last for about 4-5 days. I was prescribed medicine to help with it because everytime I used lip products, I would get the same reaction. My advice is just learn to live without raw fruit. I can have juice in moderation and even have jam or jelly but I stay clear of raw fruits and trust me I am dying to have strawberries or peaches. I hope this helps!
Instead of an allergy to fruit it could be an allergy to the pesticides and herbicides used by the people growing the fruit. Lately more and more people are becoming sensitive to these things whether it be in the form of sores, rashes, itching or other forms.
If you want to verify an allergy, consider setting up an appointment with a doctor specializing in allergies, or environmental allergies. It may bring some peace of mind.
I hope you find some answers. Good luck to you!