When you are making a dissertation defense you need to make a top notch presentation. This is done with a great deal of patience and practice.
When you are writing a thesis you need to know that it is a massive project that will take quite a bit of time. There are similarities and differences between different thesis requirements for different schools but no matter the requirements you will often feel as though you are running a race and always running out of time. You may be working on the same topic for years and as a result it will seem exhausting and at times tedious. Remember though that if you pace yourself and take regular steps you can get it done in no time.
Note that almost every university has a writing center which offers courses and writing skills tips for students of all grades. You can take some extra writing courses here or online and use them to improve your writing. Reading over previously submitted dissertations and essays can also help you improve your writing.
If you still need help try reading over academic articles will help you to embrace the academic writing styles out there until it becomes effortless for you.