you need to go be seen by a psychiatrist it sounds like you're a self-aware sociopath which is a good thing most sociopaths are devious, manipulators and major narcissists and don't give a shit that they don't feel happiness or about hurting people. you on the hand do give a shit, this will help you in understanding your issue and getting proper help.

I'm not sure if I've felt 'happy' since I was a teenager, and I'm 53. I was once diagnosed with Dysthymia, but I'm not sure that was correct; I think some low-grade, manageable depression and some low-grade, manageable anxiety are probably more accurate. (As an aside, the single most meaningful diagnosis and treatment I have ever received is that I was diagnosed a few years ago with ADD, and ritalin has improved my life a lot-- it's clear I have ADD because I can take a dose and then immediately take a nap, whereas someone without ADD would be bouncing around bursting with energy if they took one.) There is also a condition called Anhedonia, which I don't know anything about, but you might want to look up. The way that I explain it is that if most people have an emotional range from 1-10, where 1 is the absence of all emotion, and 10 is uncontrollable public weeping or shouting with joy or whatever, then my emotional range as a child was probably 1-9, post-puberty was probably 1-7, and as an adult is like 1-5. Neuropsychology is an interest of mine that waxes and wanes, but over the years I've done a decent amount of reading about it (mainly college textbooks and websites). AFAIK the consensus is still that about 50% of your personality is hardwired genetically. I completely believe this. Anyway, there are a lot of possible explanations, some of which you may be able to do something about. Don't give up. If one doctor doesn't have any ideas, see another one! Being a doctor is just like any other profession: some are good, some are bad, some just don't happen to be an expert in the specific thing that would help. Good luck!

I agree you need to see a psychiatrist or psychologist. A neurologist deals more with purely physical effects and injuries or diseases to the nervous system or brain. A psychiatrist or psychologist deals with feelings and behaviors. A psychiatrist is an MD who can prescribe medications and that’s generally the tract they take. A psychologist is a counselor trained in dealing with mental illness and related conditions - Including normal feelings. Many practices have both a psychiatrist and psychologists on staff. I am not a psychologist, but by my understanding a sociopath is capable of feelings but they are incapable of real empathy - feeling and understanding the feelings of others or caring about others feelings. But they certainty have feelings for themselves. Your situation sounds to me like it is different from that. Go to WebMd and check “Dissociation”.

Is that a thing? Because I feel like that could be my case too

Sounds lile a case for a neurologist, for a complete diagnosis and appropriate advice. If that is already the case, maybe a second opinion. If you already did that, sorry for you, real FYL, conditions like that with no treatment would be awful. If you didnt, what're you waiting for ?!