Writing Problems

When I read my writing I realised that ; I need to abate the number of times I misuse a word. I used the word "and" when I should have the word "or". Another problem I had was commonly confused words. I know them in my head, but when I put the words on paper they come out wrong.  I wish to correct this by having a parent, teacher, or partner go or my writing with me; if I can't do that I will make sure to remember which word means what. I will do this by studying the words I keep getting confused. I also have a problem with leaving out words. My problem is that I remember to add them in my head, but forget to add them on the paper. I will correct the problem by looking over my paper when I have the time or have someone else look over it. I can also write some essays in my spare time ; I feel like this will be a good idea because it will help not forget to add words. Lastly, I have trouble with timed writing because when it's close for the timer to stop and i'm not done I start to panic. When this happens I start to make simple mistakes. I plan to solve this problem by writing timed sometimes on my own.