When someone does you a favor, especially if you asked them to, don’t say “I’m sorry.”
They don’t want you to be sorry! They did the favor because they wanted to, because they care about you and want you to be well. You didn’t cause whatever burden they’re helping to carry, and you didn’t force them to help carry it. Apologies aren’t warranted.
When you apologize without necessity, you make the other person feel needlessly guilty. They start to wonder if they did cause your hardship – or at least, they may wonder if you think they did. It’s a rift for no reason!
They don’t want you to be sorry, and you have no reason to be. So replace that apology with sincere gratitude! Thank them for their help, their sacrifice, their effort. And don’t ask if you can do anything for them! Just do something for them, if you can. If you ask, you force them into saying “no,” because then it seems like they’re only helping you transactionally, when their initial effort was probably very genuinely altruistic. Just express your gratitude, and take the next opportunity you can to do something nice for them.
Accepting help is hard, and we’re all a little bad at it. But try this stuff. It helps.