Well no wonder
it depends on so many things
what friends you have
with whom u spend time daily
what u watch on tv
what u read
what u listen
what your upbringing is
what your environment is you grew up in
How your character is
what you have filtered in your head through out your life
and its nothing special bc nowerdays there are millions of Muslims who are doubting because of anti muslim propaganda and stupidity of some muslims how they are misbehaving and promoting THEIR brand of Islam.
What you need to do is feel / have islam in your HEART
from your heart you should cultivate your mind and soul with Islam and love for God.
I know so many Muslims who do not practice islam (not that its good) but they have islam in their heart and they are good Muslims.
So you are a Muslim and even better Muslim then Muslims who are doing Ramadan or even praying 5 times a day.
Its up to Allah (SWT) to judge who is good or bad Muslim. We should do the things we are supposed to do without hurting others and believe in God and wholeheartedly trust in HIM and ask him to guide you and make you a better human being.