I don't know what to do about my teeth.?

I'm currently 17 year old and going into my final year of school. I have never really cared about my teeth until a few months ago. I have never had braces or veneers, I have six fillings and a lot of my teeth are not properly aligned (albeit they are not really bad just some are pushed forward and some are back a bit). I don't really want to have braces this late in life as most people in my year who have had them have got them out or are in their retainer stage. Also, I think my teeth aren't as white as they should be, I have never smoked, I regularly brush and use mouth wash but still they are rather yellow. How much would it cost me to get my teeth straightened (braces) - Is it too late at my age? What can I do about if my teeth aren't properly straight at the bottom (starting to decay) - should I get veneers? I have six fillings, is it possible to remove these and or get white fillings - Would that be really expensive? Should I get my teeth whitened - How much would that estimate? I really hate going to the dentist, I get cringe worthy just at a check up. I don't really want to go through years of expensive dental work just so I can really nice looking teeth at the age of 22+. What should I do? All help appreciated.
--------------------
Hi, Lot of people do face problems with yellow teeth. The reason for yellow teeth can be less calcium, smoking or coffee. Some people face problems like yellow to faint yellow teeth also because of too much brushing or using products which harm teeth. While baking soda or peroxide can make your teeth white but it is not recommended. Dentists world over do not recommend use of such pure form substances on teeth as they harm your teeth in longer run. Not all whitening trays are good, in fact many people have complained about irritation and pain with trays. Yellow teeth are not always unhealthy while bright white teeth can be unhealthy. Lot of people want white teeth so that they can smile big and don't get embarrassed while talking to friends and colleagues. Such people can use teeth whitening pens which are 100% safe for your teeth. The best thing about these products is that you can easily get FREE trial to have white teeth. You may order your free trials and have white teeth. You just have to pay for the shipping and handling. Its always better to try before you buy and I am sure it will work for everyone including you. BTW the website where you can get such free samples is http://tinyurl.com/freewhiteteeth I am not promoting the website nor am I associated with it in any manner. Just trying to help someone who is worried about bad/yellow teeth. Hope this helps. Thanx :-)
Source