I don't think you've got a great hand here to be honest. The narrative isn't mine, I haven't invented it and it's supported , amongst others, by people and outlets such as Fiona Hill Former U.S. national security official to both Democrats and Republicans, Responsible Statecraft and Ukrainska Pravda as well as Gerhard Schroeder , who was involved in the negotiations and Turkish officials.
Lots of news outlets reported on the talks at the time with a similar line. The Washington Post for example reported that Ukrainian negotiators had put forward a proposal exchanging military neutrality for security guarantees.
Whether or not Putin was willing to give up his advances so easily is a reasonable debating point. However, others on here have said that his advance had stalled and was in danger of being isolated with the potential of heavy losses. Other commentators have argued that the US and other Ukraine allies' assessment was that the Russians weren't as strong as initially thought and with more arms support, training etc that Ukraine and NATO could exhaust them. Defanging was the word used on here, Johnson used the term 'to press' them.
Ukrainska Pravda was more explicit in describing the two factors that ended the negotiations. It firstly says that Bucha , civilian shelling and other atrocities was one factor . However, it also said the other factor was
So that's the narrative. Its not based on what the Russian's have said and the sources are mainstream, West supporting. If you don't believe it or don't want to believe it, that's fine, I'm not going to convince you and it won't spoil our relationship.
Personally, I just hope the war ends soon.