Is it bad im aroused by my mom?

You can't actually help what does or does not arouse you, but your feelings would not be shared by most other people. It is also important to understand that while you can not help your feelings, you are in control of what you do and say and society has laws that say that your must not pursue these feelings. It is probable that as you grow older, your feelings of attraction will focus on females that are not part of your immediate family, try and socialise with some of these.