Why?

Why is it that when you're making slightly more money (in my case, it means my bank account isn't a big zero), you seem less inclined to spend it? Or is that just me? I'm stressing myself out by working round the clock, leaving no room for fun. When friends ask me to go out, I say either I'm busy or I'm too tired. Which is true anyway. But I'm beginning to suspect that I'm developing an addiction to the secret masochistic delight people derive from saying they're too busy or too tired. Like their time is so precious that they can't be bothered with extravagant frivolous things anymore. They're mature and responsible and they have a plan and a purpose, big important ones that give meaning to their lives. I'm sure it's all very good but they just look pompous to me. Meanwhile I don't know what I'm supposed to be doing with this money. It's too little to be used for anything grand anyway. So it stays where it is. I feel guilty if I want to spend my money but then I feel oppressed if I can't even buy myself a treat and I'll feel sorry for myself and this battle plays out in my head over and over again and drives me to exhaustion. On one hand, I like knowing that I am finally capable of making money without spending all of it within days of earning it but on the other hand, the relentless pressure of exercising self-control and keeping a tight rein on my hedonistic tendencies is seriously taking its toll on me. I think it's going to take me some time to deal with this financial immaturity. It is all so so sad.