I really need you to check these sentences. Thank you very much!

1) I fell off (do you need a word afterwards, e.g. my bike) and I bruised my knee. I cleaned the wound under running water, then I dried the area and I put a dressing (a bandage over it)/I bandaged it.
2) I probably didn't clean the wound thoroughly enough, as it hasn't healed (up) very well, and I think I have got an infection.
3) The doctor prescribed that I should take (?) a suppository of Paracetamol every six hours.
4) Big Brother represents a threat to his citizens because no one has ever seen him. On posters which hang everywhere he is depicted as a black-moustached man gazing down over the caption "Big Brother is watching you".
5) The doctor prescribed total bed rest for two days.
He said I should rest/stay in bed or two days.
I should rest the ankle.

1. ... fell off my bike ...

Put a semicolon after 'water' or else you'll have a run-on.

2. No need for 'up' or 'got'

3. Replace 'take' with 'use'

4. Closing quotation marks go after the period at the end since the quoted words make a complete sentence.

5. OK