I coughed because I have cold.
>> I cough because I have a cold.

I'm very sick.  Almost correct!
>> I feel very sick.
I want to be healthy and fit. Correct!

REMINDERS:
1. Always be reminded that if you are writing a sentence and you are referring to present time you should use present tense.

2. Always remember to choose the most appropriate words for your sentences.

Comment:
Hi, Emma!
Thank you very much for coming in our class. I hope to see you again next meeting. Please, take note of my reminders and see next time you do your homework avoid these lapses above. Thank you!
-Teacher Joanna