Should i be feeling guilty and am i selfish ?

Dont feel guilty. You are smart to think about what is best for yourself and your baby. If your dad is an alcoholic he is selfish and he only wants you to stay as a housekeeper. I dont know how old your sister is but she is probably worried about being alone. I would advise you to talk to your sister and let her know you are not trying to hurt her but you need to do whats best for you and your baby. If you can visit and let her know she isnt alone it might make it easier on her. Good luck and dont let anyone get you down.