Something like a fat fetish but not exactly.

This is really hard for me to write because I don't even know what's wrong with me. The thing is, I'm perfectly straight. Always have been. And all the guys I've ever dated were overweight and I do have a liking for chubby guys in general. I thought it was normal, but then I realized it's not only chubby guys I'm attracted to, overweight girls turn me on even more, hell, the mere topic of gaining weight and being fat turns me on. I've looked it up recently and found out about the whole fat fetish thing. At first I thought that's what I had, but as I read what people say about it I realized it's not the case. People with fat fetish tell stories about how they struggle with dating skinny partners because they keep thinking about feeding them or wanting them to gain lots and lots of weight and they don't sexually satisfy them very much because of that. I'm not like that. I have a boyfriend that I love and we've been together for three years and yes he's overweight and I'm attracted to him, but I know I won't be any less attracted if he's skinnier, and when he tries to lost weight I only encourage him because I care about his health. And I have no fantasies whatsoever of feeding people... I do however get turned on by the thought of someone gaining weight, or when someone talks to me about it. I think it's getting out of hand because I like to write and one of my characters used to be fat and now every time I write something about that I get turned on. I hate it. I hate it so much and I don't understand it and I don't want to live with it. My friends, especially the girls who have plenty of extra kilos on them, would be disgusted if they knew how I felt when they talked to me about their weight.

I know this is a long post, and I'm mostly rambling but I had to get it off my chest and see if someone would understand. If anyone has any idea what's wrong with me, or if it really is fat fetish that I have, please tell me in the comments. Thank you for your time.