Correction of a short paragraph

With regard to my English knowledge, I have been fairly intensively studying English for over two and a half years without any major breaks. The culmination of my endeavours was the CPE certificate which I have successfully obtained. One piece of advice I can give you is to pay scrupulous attention to every single letter of words you come across. Every time you will not be sure, just consult a dictionary. I personally got into the habit of looking up words every time I feel the need to do so. Another piece of general advice is to read as much as possible.

Could you please correct this paragraph?

Thanks a lot in advance.