There is always enough supply to meet every demand. The Universe has plenty to provide. You just have to ask for it. One reason you don't have as much as you want is that you're never taught to ask for it. Another reason is that you think it's wrong or selfish to ask for things (you're taught that too as a child). And I'll bet you also may not know what to ask for. I'll be talking about each of these points here.
Even if you can't see it, there is plenty of supply out there. Often what happens is that there is a demand and as a result another alternative is created. For example, if you allow yourself to believe that the world has run out of energy sources, you may create those circumstances. Look at the fact that hybrid cars and electric cars were created when the US started having problems with oil supply. That's what happens. So rest assured that there is always enough supply for any demand - even yours!
There is a famous quote from the Bible - "Ask and it shall be given." That is the truth no matter who you are or what you believe. You are never taught to ask for more. In fact, you were probably told that it's not nice to ask for more than "your due." If you believe in the Universal Laws (one of which is the Law of Attraction), then you should try asking for what it is you want.
Were you taught that it is not nice or selfish to ask for things? Were you always told that you should be content with what you have because there are others who don't have anything? If so, this is a limiting belief that you must work to clear from your subconscious. It is right for you to ask for whatever it is you want or need. Make the affirmation "this is what I choose and it is mine by Divine Right." Remember that if there is always enough supply for any demand, then everyone can have whatever it is they want - they just have to ask for it.
Do you know what it is you really want to ask for? Are you one of those who bounces back and forth about what you want? One day you want a better job. The next week you want a raise in the same job. Then another week, you decide you don't want to work at all. How on earth is the Universe supposed to know what it is you really want? You have to be able to determine what you want and then you have to define specifics about that particular desire. Don't just say "I want a new car" because if you do, you're liable to get a car that's not really what you want or one that you're happy with. Write down what color, what make, how much horsepower, how many doors, what miles per gallon etc. Write down everything about your goal. Then you focus on it and you'll be much more likely to receive it.
The next logical step is to learn how the universal laws all interact and how you can actually put them into action to create what you want in your life. You can find out exactly how to create your ideal life in The Art of Making Things Happen