I saw this sentence
"中学生の時、みんなでやる行事はほとんど手伝えなくて。私はあまり学校行事に出ませんでした。手伝っていないのが申し訳なくて。"
The context is that character was invited to go out shopping in preparation for a school event, and he wondered why as he hadn't really helped before and was very happy about it.
My question is why there is -なくて at the end of the first sentence, but then there is nothing. I've learned that it means "Do not do something and~", but there is nothing after, just a punctuation mark. Is it related to the next sentences after that one? Or is something else at play that I don't know yet?
