Plenty of info and experiences in other threads.
Bottom line is that after a few month, it will wear on you. Right off the bat you think its great to be able to travel and be paid for it but spending 150+ nights in a hotel room may make you miss home.
Not sure how often you see your GF but you'll see alot less of her and miss out on alot of things you used to take for granted in your hometown.
And with all the time away, you'll start to think about paying your mortgage but not even living in your home.
On the other hand, you're young and not married (yet) so you really don't have anything tying you down. Who knows what can happen on the road. You may find you want to live in another city and this is a good chance to try it out without permanently setting roots.
Everyone is different so until you try it out, you won't know for sure.