I have the identical problem, I bought a single do it yourself a single from Amazon (rubbish) and also a pack of two from Boots these were fantastic but I found them as well difficult to mould and in the event you fail to fit it correct right after two goes then the mould needs binning, so unless your confident with them I'd give them a miss.

While the dentist is expensive (I paid 100 for mine) it is tough, longer lasting and will most likely save you cash in the long term, plus its improved fitting. I would def go for this solution.

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