I draw and write all day, I also do things like handstands and push ups that all put strain on my hands and wrists and its been hurting so bad I can now barely draw or write. My left hand is really important to me how can I preserve it?

Give yourself a break! You need to rest your wrists and hands if they are hurting you, that's your body telling you....enough! You could try some ice to the area when you finish what you are doing....but pay attention to your body, it does wear out after repeated use!