Greeks do use garlic but not as much as the French/Italians/Spanish they do use a lot of onion if this puts you off trying then you can stick to the fresh salads and say top it off with barbecued meat or fish or you could try a gyros but tell them NO Taziki [this can contain a lot of garlic]
my OH is not a lover of the garlic and onion but has always found plenty to eat

wizard

There's no problem with garlic. Just look at any of the fresh fish tavernas in any of the harbours and garlic is a No-No.

Fresh sea-bass, fresh anything.

Tsatziki is usually provided as a starter with the bread. I can't stand yoghurt, (psychologically), but love tsatziki, yoghurt and garlic with cucumber.

It's all in the mind till it's on the waistline.

Parky

garlic is used in much of the meals that are oven cooked and in a sauce but if you have grilled meat (or fish as Parky 45 points out) garlic is not a usual addictive and if you don't like herbs on the food just ask for it 'Sketo' as you would coffee when you don't want milk or sugar.
I've only been to Crete twice, once to Georgopolis twinned with Paleochora and last year to Myrtos and must say that the food in Paleochora and Myrtos was fabulous. You shouldn't have a problem.

I cannot take garlic - I like it, but it don't like me. I simply say no garlic please. Like in a curry house I ask for Dall, not Tarka Dall, coz it's got no garlic.

...ok, I'll say it before you do. Tarka Dall is the same as Dall, but 'otter. Geddit? Oh nevermind :O)