いっぱい・たっぷり～する

got/need something fix

(addicted to it)

I got ramen fix last night.

昨晩ラーメンを思う存分食べた

I got marathon fix last weekend.

先週末に存分マラソンをしたよ

I need chocolate/movie fix.

チョコレートが欲しい/映画が観たい

When you've been craving fast food or haven't had it in a while, you might go out and eat fast food/takeaway food (usually a lot of it!) therefore satisfying the desire to eat it. Like fixing up the fast food shaped hole in your heart.