Have you ever just felt so alone and didn't know why?

I have everything I could possibly want...a fiance who loves me, friends who love me, family who loves me, a great job...I even have a cat that is like a kid to me...but then someone please tell me...why do I feel so alone? Like alone inside my head...not crazy...just like no one understands...all of my good intentions are worthless in everyone's eyes as if no matter what my intentions are, they're still shit...bad...

I've never been a selfish person in my life...or at least I have always thought I wasn't a selfish person...but it's like one time I feel I NEED to be selfish for myself...I'm wrong for it...Idk...I'm stuck between a rock and a hard place and doesn't look like anyone's coming to my rescue anytime soon.

Hmm...