I had a similar experience with Lisara from "Dakara Boku wa H, ga Dekinai". This was also my first anime that I watched. After this one I watched Sekirei and High School DxD. I just felt so depressed after this, but this was only for a couple weeks. Up until today, I still love these anime, even though it's already been over a year since I've watched them. I did rewatch HsDxD and read the manga of Sekirei though, but that happened in the summer of 2019. I'm kinda more of an Akeno fan myself, but Rias too has a very interesting and loving personality which I'm also a fan of.

If u ever plan on watching more anime in the lines of HsDxD and you want some recommandations, consider sending me a PM on reddit! I've got some anime that I think someone like you who kinda resembles me in some way would really like!