Poli Sci major - check
German minor - check
Year in Germany - check
Want to come back - check
Offer of place to crash - check
That was me 16 years ago. I'm still here - and there were some very lean years - but life is cool. Be open minded about where you live (for example, I had wanted to go to Heidelberg, Frankfurt, Hamburg or Berlin, never Munich - go figure), and what you do and then be prepared to teach yourself whatever job you end up doing (why on earth they still offer poli sci majors and sell them as a ticket to any job is beyond me - IMHO it's only good as a pre-law major, unless you quit before law school as yours truely, but I digress)
Anyway, take your friend up on the offer and think about any other skills you have. Big important question I didn't ask myself for a long time - what work would you do if you were to stay in the country? Build on that as well. Good luck. PM me if you have any other questions..
EDIT : I just saw your profile page - do not be proud and DO take advantage of all the offers you get as a "young person" ( I didn't) . Germans your age are just starting university and you will not be taken seriously as an employee for a long time (this could vary in some companies). I was 22 when I started at the company I, still, work for - the first 3 years do not count towards my retirement, I was paid considerably less than others because of my age only, etc. Enroll at the hochschule for politik (downtown munich) and work part time (I almost did this semester but I can't cut my hours at work

) If I had it to do over again, I would. But then again, I was so busy partying then... And do not be offended if none of your studies are recognized there, or only a few courses are. (Took me awhile to get over that myself - especially since I studied 'Politik' for two years in Heidelberg and know what they actually did... )