Could you please proof read my written work? My happiest moment this year was when I saw Ed Sheeran in concert. I was excited because it had been a long time since I attended one of his concerts. His performance was so amazing that I still bask in its afterglow. "Going" is not a "moment". A "moment" is an instant in time. "Going to see him" is a noun that does NOT name an instant in time. "When I saw him" does name an instant in time. In this context, "since I had attended his concert" is probably wrong because it appears to name a specific concert. If that is what you wanted to do, it would have been better to name that concert: "since I (had) attended his June 15 concert". "Had" is not needed and is better omitted. "Had" pushes the action further back into the past, but the word "since" already does that for you so "had" is serves no real purpose. Your third sentence is not wrong, but "and" is not a good conjunction because it does not express any relationship between the first and second clauses. Although it makes sense to "bask in afterglow", it is better to specify "its afterglow".