I'm stuck on the following clues and would appreciate any help. Thanks.
20 across- Water running out from ship(6)????E?
21 across- A river drowned valley,creating difficulty(6)??????
4 down- Roundhead in green,merry almost(9)O???E????
5 down- Person interrupting Mac's nap is tedious(7)O???O??
15 down- Lizard gets painful swelling sitting on one stinger(9)????I???P
18 down- Confused, having shown signs of injury after punch(7)??????D