It seems that you have some kind of depression to me. Usually "normal" people have an "optimism bias". That is to say, they view things better than they are. This gives them hope to continue.

However, and at the same, and from an evolutionary point of view, we are hard wired for other environment. For an environment where there is no continuous stress and work, and where the social bonding was very strong in groups of 50-100 member tribes. However, under our current world, we are stressed all the time. No wonder why mental illness is pervasive. We are adaptable species, but we are prone to be negative, because in the past, being negative gave us a survival edge. That's "why zebras don't get ulcer" as Dr. Robert Sapolsky said, because they are stressed only when there is a predator in the vicinity. For us however, we are stressed 24/7 in our current environment. We need to program our minds consciously how to be positive. It is not the default response.

Do we deserve to be happy? Yes. I believe happiness is the ultimate goal of life. Why? Because negative emotions are painful while happiness is joyous. We have the instinct to live (it is not a choice, it is a give), so we have the responsibility to live happily. There is no other option for living, really.

Your physiology is also affected by your feelings. If you are stressed and depressed most of the time, it is more likely to catch a disease and die earlier, because your immune system will be in sleep mode during these times, while if you are happy and positive you are more likely to be healthy and live longer.

Hope you will feel better soon, and I am sure girls would accept you as you are if you try. Just try not to tell yourself negative things, because they will be programmed in your subconscious mind. That is why you began to believe these negative thoughts, because you repeated them again and again in your mind.