I am almost afraid to say anything I.C. Cause It sounds like I am being super critical when I am trying to be helpful. Let me know if I am going overboard on this. You know how obsessed I am about words.
You have a real Tom Petty feel to this tune. So much in fact that I would be concerned with the last 3 lines in your chorus. They are dead on in cadence and melody to a Petty song. I don't know if that is ok or not.
The first verse seems a little forced to my ear.
The second verse, you changed the focus in the last line from you to her. You could change it to We wrote or sang.....I painted.... I get an image of you under a tree instead of sitting or sprawling under a tree, if you get what I am saying. Could be just me.
I get what your going for. The guy has been hurt before so he is a little scared to commit to his feelings. Is that how the Autumn moon heart verse fits in. Autumn being about endings. He is going to take back his heart after the break up or is it about love not returned. It could be just me, but I think you need a line that makes the underlying theme a little more evident. I had to read through the lyrics 2 or 3 times and think about it to get a feel about what was going on.
I really do like your tune and the sentiment. I look forward to hearing the finished piece. As always feel free to throw out everything I have said or keep what is useful. Songwriting is so subjective, but I know you are writing from a commercial standpoint so the criteria is much more finicky.