I feel like a coward every time I walk past a person in need and don't help
What has led to this feeling of cowardice every time you don't help a homeless person?
I don't want people who need help to feel like I'm selfish...
You have no real duty to help everyone who is homeless, but it depends on their situation and yours. If possible, just give a few coins instead of a lot of money, because that is something at least. You will still continue to feel bad if you don't do this.
True...I feel so horrible if I don't help. I wish there were more people who could help homeless people.
It's great to hear that you care about the homeless and want to help out! Hopefully you feel better when you are able to give at least a little bit.