This might be upsetting, but I'm here to help.
I made this image, please steal it, you'll need it one day.
It's not so bad! We can calm down because you already know you're an animal. You're a multicellular organism that has cells with a nucleus and no rigid cell walls. This puts you in the same boat as horses, bugs, jellyfish, sea cucumbers, corals, and sea sponges. Our last common ancestor with sea sponges was 700 million years ago, but neither of us stopped being animals. We share the common ancestor of all animals, which is the true definition of what an animal is but that's a lot harder to decipher. I don't think an alien would be an animal, even if it resembled us.
What I'm suggesting is that we put our feelings aside as to what should be a fish and apply the same logic we do to animals. If we look at the definition used to decide what the first fish was, we have a common ancestor of all fish! Everything descended from that fish would be a fish too! To be a fish, you need a skull with a brain in it (craniates). Some definitions require that as well as a spine with a spinal cord in it (vertebrates). Those parts don't have to be bones, bones come later. Our first fish appeared 530 million years ago and was a cartilaginous, jawless fish like this Haikouichthys from Nix Illustration. It's about an inch long and had four eyes.
Today, our closest living relative to Haikouichthys is a Lamprey, a cartilaginous sucking fish with a bunch of teeth. They split off before the first jawed fish appeared. Since you share a common ancestor with all jawless fish, you are a jawless fish!
"But-" you say, moving your jaw. Worry not! All jawed fish (gnathostomes) are jawless fish. When the jaw first came around, it was a big deal! Two now extinct groups took off, the placoderms and the spiny sharks. They lost and don't exist anymore so I'm going to move on! From this same time period we get two other groups that make up all living fish today, Chondrichthyes and Osteichthyes. The Chondrichthyes are all modern jawed cartilaginous fish like your sharks, rays, skates, sawfish, and chimeras. The Osteichthyes contains all bony fish, or every living thing ever that has bones. You are not only a jawless fish, but also a jawed fish and a bony fish!
Now here's a split where you get a break. Lobe finned fish vs ray finned fish. Lobe finned fish have bony, stalky "arms" before the rays of their fins start where ray finned fish start their rays asap. Lobe finned fish became the top dogs in fresh water up until the massive extiction event that started the Triassic Period. The first fish to walk on land were lobe finned fish. The bugs had already been on land for 100 million years so it's more of a personal achievement. The bony stalks allowed for more muscle attachment and more weight to be applied, giving rise to the Tertrapods or all vertebrates that have ever lived on land. There are now only eight species of non-tetrapod lobe finned fish. There are two species of coelacanths and six species of lungfish. All other bony fish are ray finned.
So you are an animal, a jawless fish, a jawed fish, a bony fish, a lobe finned fish, a tetrapod, a mammal, a primate, and yourself. You are a fish! Is the whale shark still the biggest fish in the ocean? What's incorrect about the fish in the mirror image? What animal loaded for you on this page, is it a fish? Does this page need rewritting? Let me know in the comments! I'm happy to change or rework this page to make it better because it's pretty important.