It's time for a change

Soooo. Today I had sex with this lady who works at the subway up the street. She's in her late 40s maybe early 50's. I told her we were gonna just smoke today but after we smoked I started trying to fool around. Eventually I talked her into to going back to where I stay which I didn't want her to come in the house (my parents house) because I didn't want to disrespect my parents house. So I had sex with her in the garage. After I had sex with her I just kept thinking to myself that this women is struggling and just trying to work a 9-5 trying to go to school and make something out of herself. I don't know her demons or what she struggles with but that doesn't matter. I just don't want to feel like I'm taking advantage of her. I mean she clearly wanted it as well. She told me herself she enjoyed it. But in the past I've had a issue with just having sex with a woman and then going cold and ignoring them and leaving right after I'm done. Which is what I did. I dropped her off back at her car when we got done but I felt like shit after. Because she was so nice and by the way everything went down I feel like she's been used alot in her life. I feel like crap right now. I don't want to be a sexual deviant. Just using people for sex and not showing any compassion for them or getting to know them. She's trying to go to school and she works like 3 jobs and is always busy. Don't get me wrong I'm not soft or a wimp. It's just the fact that she was older and Is trying to get on her feet. And I feel that I had no business messing around with her. Cause I don't plan on being friends with her or to even hang out again. I feel that I I don't deserve a real relationship for being so cruel. I didn't say anything bad to her matter fact I was super nice. It's just I knew what my intentions were and I'm tired of living like that. I've done it alot before but this one really made me think. Does anybody out there feel or understand where I'm coming from? Please reply