You'll probably get ten different answers to your questions. But I suspect you already know your symptoms better than any of us can tell you. You sound really aware and that helps a lot.
My guess is it's depression and maybe a little anxiety. The depersonalization sounds like depression as well as your not feeling love for people whom you should feel much warmth for. Depressed people don't feel very much except sadness or the blues and worry a lot. Sometimes they don't even feel that, they feel just empty.
If you feel that you have a mental illness you should visit a psychiatrist. There are a few different classes of meds and with them docs can treat almost every symptom that makes up a variety of disorders. Depersonalization is hard to treat but it doesn't sound like your worse problem. Sounds like your worse problem is concentrating on reading and it could very well be caused by a lack of concentration or it could be problems processing information, which doesn't seem likely as you don't mention any other information processing problems so I would rule that out and say it is the concentration factor that you mention. Which indicates it might be depression, as well.
Only a psychiatrist can determine what is wrong with you and they do that after a few visits when they gain full perspective of your personality and symptoms and guage your reaction to whatever medicine he or she prescribes. Generally, if they detect that you are ill and determine what your symptoms are, they prescribe medicine on your first visit. They also tend to ask you what you think is causing the symptoms and they listen closely to what you have to say. It is a fairly easy process to go through and lasts about an hour after which you head to the pharmacy and hopefully make a complete recovery.
One thing most people don't realize about mental illness is once there is something wrong, it generally doesn't clear up by itself unless it is depression or latter stage Schizophrenia, and most illnesses require a lifetime commitment to medication. It can be worth it to stick to a person's meds and take them religiously as most people, with treatment, can live a relatively normal life free of any symptoms if they simply allow themselves time to adjust to the routine of having to take medicine and enough time for the side effects to stabilize.
Some people are afraid of psychiatrists and perfer therapists who can't be of much help when there is a clinical problem inside the brain. Therapists are great and can help people cope with stress and behavior problems but they aren't qualified to treat any type of illness with medicine, they can only counsel. A psychiatrist prescribes medicine as well as counsels.
If you think there is a pattern of illness to your thoughts and behavior don't be afraid of going to a psychiatrist and getting a professional opinion. It doesn't indicate that you are 'crazy' if you see a psychiatrist for suspecting an underlying problem causing your symptoms, it meens you're smart and want to get well
