Hello dear native speakers
Is the following sentence well-formed ?
Does it flow well?
My gransdfather did everything in his power to help his brother overcome his drug addiction, but you know the success of such attempts depends on the patient's willingness to try to solve his problem, which his brother didn't signal any.
I doubt about the end of the sentence. Should break down the sentence into 2 sentences? If so, how can I do that?
Thanks in advance