One need to be strong to be a foreigner. Anything "normal" requires strength and patience as a foreigner is not allowed to be normal. We are required to prove ourselves over and over, only being three times better than a local is that will make those locals find you reasonable, or even mediocre. Having any accent many times is synonym to be stupid and incapable. Never mind you speak your own language and THEIR language, that rarely counts as a sign of dedication and willingness to overcome barriers.
Being bitter is normal. Many times we are stripped of our smiles and our faith in justice or good in other human beings. I know those are moments and not life itself. But sometimes it hurts, and at least for me, I can only dream of those times when I was quietly happy at home, having diner with my parents.