[It takes a moment for him to answer, because he is focusing on breathing and not letting any emotions slip. No, he's not saying this to vent, he's saying it to make a point to Sayaka. So he needs to get to that point.]

Indeed it is. And while it is not exactly the same as your situation, it is still very much 'a bad thing', and I feel like I can say the following with some confidence:

That feeling of 'am I really doing enough' never really goes away. Try as you might to do the right thing, there will always be invasive thoughts. But those thoughts alone do not define who you are. No matter how many times you have the thought 'maybe murder is the answer', what matters most is that you follow that thought up with 'no, that is wrong.' Which you have done, time and time again. And that effort, that decision on your part not to follow through with those thoughts, that is 'enough'.