"I was suddenly tired: the kind of angry-tired that’s irritated by everything that isn’t flat, and white, and has a pillow at one end." This describes a bed. A pillow, and a white, flat, surface. This means the character is very tired and wants to sleep, and nothing BUT getting some sleep will make them happy. ‘If I thought you were that kinda guy, I wouldn’t have let you get near her, or any girl I know.’ I'm not quite sure what that means. Is there some text or conversation before this? Who is saying this? Hope I helped, if I misunderstood, feel free to tell me. :)

The first sentence does need some work. I think the best way to put it is by saying "I don't have a proper life." which means you aren't living a genuine life, or that your life is not living up to your standards. The second sentence sounds good. Another way you could phrase that is by saying: "I'm not properly enjoying life."

An "ache" is a persistent feeling of discomfort, like a headache. Example: After I ran a mile, my legs ached. "Pain" would be immediate discomfort, not persistent. Example: When James punched my arm, I felt great pain. You can also use them both in a sentence. Example: I felt such an aching pain in my back. This would mean that you feel a persistent amount of discomfort.