This.There are so many reasons that she’s not responding which you aren’t considering.
We all do this at one time or another. Make assumptions based on what we fear. "I'm a burden. That's why she's not getting back with me." When, in fact, she could be busy with...well, just about anything. Or, she could be deciding how to respond.
Making these kind of assumptions is, I've found, really harmful to ourselves in the long-run.