You are a good student since you got 55+ marks in 3 attempts in Accts, cost & Fm. I assume you are good too in taxation. If theory is a problem for you, make notes from module or any text book like munish bhandari.
By making notes you will remember theory more effectively and will practice of writing too.
Improve your presentation and hand writing (if bad). Write neat and provide proper space between words.
Revision is very important. Make small notes for revision on your own. For more tips to cope up with theory, search tips on caclubIndia. go to profile of legends like Ankur Sir and others