Let me tell you that, to answer the first question about what to change, it doesn't take much to make an impact on a room. You do NOT have to change every single thing in your room or spend a ton of money to make an impact on your home decor. It can be as simple as giving your room a new coat of paint or changing up a centerpiece on a coffee table or the kitchen table with a new item to give you an updated style. Maybe your mantle needs a new focus. So remember one nice new something for your home can make your room feel brand new and give you a much needed boost as well.
Why do you want to change it? Well, if you change everything all at once, it can be costly and who has the money to do that as well as the time and energy? Well if you find a new style that you like, make a list and prioritize what is most important. Then buy a little at a time as it makes it affordable to make changes. If you don't take an honest look at least once a year, then suddenly you may find your home a little faded and jaded.
Remember just because Aunt Milly gave you that vase, it doesn't mean you need to keep it for 20 years. If you feel guilty about getting rid of it, then give it away to someone that admires it. They will love it and so will you!
Now, I am going to tell you that before you get something new, make sure that you buy something that you can find more than one way of using. Don't spend the money on something that you will tuck away in your closet for 8 or 9 months out of the year.
I love products that are not only beautiful but useful. You also need to look at quality. If you do not by something that is well made, it will fall apart before you are ready to change it up and when that happens you will be sad. Believe me, I have learned this the hard way. So it is worth it, to spend a little more.