I feel like a monster, how can I debate thoughts that say I'd hurt my pets or loved ones? I don't deserve them at all.

When I was a little kid, I used to be horrible. Every time I thought an animal was too cute or something, i’d get violent, terribly violent. I regret it so much and wish I never did anything like that. It follows me in my mind and I hate it even though I was a child. Then a year or two ago, I got upset at my cat and tossed her onto the bed very quickly and hard, and pushed her down. I remember feeling like I didn’t want to hurt her but I didn’t want to let go. I cried after it happened and gave her many treats. Around the same time, my dog got me mad i just smacked her nose but I still feel sick to my stomach thinking about it. Idk if i was 14 or 15 at the time? I would never do anything to hurt any animal now, but why did I ever do it back then? It makes me so sick thinking about it and now I can’t STOP thinking about it. I still never wanted to hurt my cat, but she got on my last nerve at that moment and it happened multiple times and I threw her pretty fast. I can’t believe I’d ever do that. I’ve been hating myself for it ever since i started thinking about it again. I can’t forgive myself and Idk what to do. I wish I could go back in time and never do what I did. She was still only about 5 months old at that time. She means the world to me and we have a very close bond, but now I feel like I can’t love her because what I did. I feel like I can’t have friends, or anything really because I feel like I don’t deserve anything. I feel like a terrible monster and I hate that I ever did anything to a little angel that didn’t even do anything wrong. Idk how to forgive myself. I hate that I did that and I wish I never did. It still wasn’t as bad as it was when I was little, but it’s still not okay at all and I can’t go back in time and change it, so now idk what to do with myself. I feel like I don’t deserve to be around my cats babies even though I love them with all my heart. I’m 16 now and not the same ragey person as i used to be. I had a lot of anger built up from an ex that I was with at the time, but still WHY would I take it out on my beautiful cat. The more I think about it, the worst it gets, it’s sucking up all of my happiness.

Does anyone else experience this lingering fear and anxiety because they think they’re capable of hurting someone? It’s killing me. I feel like I’m such a danger. I feel like I’m a predator. I feel like this awful person and I can’t shake it. I want to carry on with my day but I can’t. I don’t feel like I deserve it. I feel like I’ve done awful things. I can’t stop crying.

I don't even know if I should put this here, but I have the greatest girlfriend in the whole world, and I love her very much, but my thoughts keep saying I'm going to hurt her, so I can hurt God and idk what to do, I feel so disgusted and idk what to do, and the worst part is why does some part of me just not even care idk what to do anymore, it's almost like I'm turning into this horrible person and idk what to do, I'm really not sure what to do. I have really been able to be happy I just feel like I don't deserve it and I want to care about people and God and I want to be a good person, but a part of me shuts off my caring nature and idk what to do, I'm really freaking out because it's like IDC and idk what to do I just feel so nasty and scared because why don't I feel like I care. Why does it feel like it's something I wanna do idk, what to do I'm really freaking worried. Also I don't want OCD but a part of me says I need it or I like these thoughts and idk what to do, as im writing this i just feel like laughing and idk what to do, i really judt want jesus to hug me and say everything will be alright, i am such a monster....