Some excellent work sheets and advice here.
The BBC no longer updates this web site but what is already on there is very good and free.
http://www.bbc.co.uk/learning/subjects/english.shtml
Here is my corrected version of your first paragraph>
>
Thanks to all for the answers to my question,but my English problems are huge, and I have been struggling with it for a long time now. It's not only grammar I am having trouble with, but a wider range of things.
Grammar, punctuation, spelling and understanding what I have read.
Also do not use single letter abbreviations such as 'u' for 'you' and 'c' for 'see' or 'r' for 'are'. That really does make it hard to understand.