As @Sub.Zero describes recon, the anger you’re experiencing now might come from a profound gap between your old self and your new self. Your old self would’ve loved to help. Your new self wants to put up a boundary and say no, because your mower is already doing so well. So part of you is saying “no!” and the other part of you is saying “well, maybe!”
If you were 100% this new person, or 100% the old person, the problem wouldn’t upset you. You would just do what you always do - always self-sacrifice, or always set up a boundary, and never give it a second thought.
But now it sounds like you’re in a situation where you know what to do, and you know that it’s the right thing to do, but you haven’t exactly figured out how to do it. The subconscious mind is telling you to execute based on beliefs it has, but those beliefs are new, it hasn’t practiced ACTING on those beliefs. The subconscious mind is AHEAD of the conscious mind.
So you’ll need to practice being the new person you are, saying no, standing up for yourself, seeing how that feels, and then building on that experience by using it as a memory that reminds you setting boundaries has positive effects in other areas of your life, as well.
If not, if you go back to old ways and relent, you could seriously damage the subliminal process, because you’re teaching the mind that even with these new beliefs you now hold, AKA better beliefs, the conscious action and response to those beliefs is the same as the old action/response to the old beliefs. And then all that will happen is you’ll have different beliefs about yourself, but the exact same external circumstances, and life will be only moderately better.