What i have found about breakfalls is that it is all about trust.
You have to trust yourself that you can do it without getting hurt. If in doubt you probably have to spend more time doing basic falls until you become proficient enough to advance to breakfalls.
Then you have to trust your partner with your life! The difference between a nice breakfall and ending up in the ER room with a broken collarbone resides in your partner's ability to hold and support you during the whole cycle of the exercise.
And yes, it takes time for some people. I could hardly execute a breakfall without getting hurt before shodan, others were good at it at 3rd kyu already.
Take your time and keep practicing. Safety first and you will be fine.
If my ukemi depends on someone else in any way beyond the initial taking my balance, I am doing it wrong. My ukemi is for keeping me safe, no matter who is throwing me and how......