Is your pony a unicorn?

Ponyfan

Definitely not ruined It looks fine to me, but of course I don't know your cat. If the black outlines bother you, maybe you can soften them a bit by adding more white over the lines? What kind of paint are you using, is it acrylic? If so, you can safely add more layers where needed.

Portraits are very difficult, it's one thing to have the technical skills to draw a cat or a human, but capturing the likeness of an individual adds a whole new layer of challenge. I think it still looks like the cat in the sketch, but I get your frustration. I often struggle with turning sketches into finished works, whatever the medium. It's difficult to maintain the expressiveness of a sketch, it takes a lot of practice and familiarity with your chosen medium that may behave very differently from pencil, which allows you to do very soft and subtle shading. I also very often feel like inking 'ruins' my sketch in a way, but I'm sure no one else would see it like that, it's all in my head.

I hope this helps you feel better about your work, and gives you courage to continue finetuning the piece if you think that is needed.

Is your pony an earth pony?

I was surprised the Firefly shirt was still around too It's one of my favourite MLP shirts, I wish we had Five Below here in the UK!!

Me too! I got the white one as well. I love those shirts, very comfortable!
I haven't found the styling head yet, but why does it look so... Odd?