What a great opportunity you have :)
Spanish is a beautiful language, though I am a little biased. Well, I think German is beautiful also.
Yes, German is hard. So is Spanish. Languages are like this, you get out of it what you put into it. I used to speak German, and moderately, but as I didn't have much practice, I lost it. Language is a skill, use it or lose it.
German is closer to English (As they are both Germanic languages), though English has been waaaay more derived since its origination. Any language is worth learning, but you have to give it your all. Languages are big, and what you learn in school barely gets your feet wet, so think about that.
Also, if you live in the US, Spanish would likely be more beneficial for you to learn, I wont lie. There are millions of Spanish speakers here in the US, besides it really is a very pretty language. So if you do it, and continue it, it would be worth it.
Not that German wouldn't, German is really a wonderful language as well. The culture is beautiful. Any language you learn is useful to you, whether or not you pursue it later in life. It really helps expand your knowledge and you grow as a person, at least I think so.
Just review each language and see what you like better. Its a matter of personal decision, really. Best of luck to you :)