Easiest language for English native

I only speak English, I wish to learn another language.
The problem is that I've always kind of sucked at learning languages. I learnt some Indonesian, French and Japanese in school (Australian), and I was always terrible.
I understand that the more languages you learn, the easier it gets to learn more, is this true? What are the easiest languages to learn as an English speaker? Dutch and German?

>>7
>Nobody is naturally good at learning languages

There are. Just like there are people who are naturally good at other things. Some types of savants even do it for fun. Your point still stands though.