How to put yourself first without feeling guilt?

This is going to sound really bad, but I don’t know how to put myself first. I am a people pleaser to the max, and I am very extroverted. I would carve out my left lung if someone needed it. I recently moved into a new city, and I’ve been financially taken advantage of twice in the two weeks I’ve been here.

I don’t know how to say no. I don’t know how not to give my money away to every person I see. I constantly put myself down to lift others, and I see it’s a problem but I can’t help it. I got really sick a few weeks ago when it was really cold in the morning because I gave my jacket to someone else because they were cold.

How do people not feel guilt? I can’t not help people, and I can’t tell people how I actually feel. I only feel good if I’m helping people, and I don’t know how to find self love and self appreciation. How did/how do you self love?