A thrilling fourth-round encounter at White Hart Lane saw the League Two outfit take a two-goal lead over their Premier League opponents by half time.
The hosts went on to draw level but a Garry Thompson goal appeared to have sealed the win for Wycombe, only for Spurs to score twice in the dying stages to knock the visitors out of the Cup.
Ainsworth told BBC Sport after the game: "The last 10 minutes, I don't know where to start. It was after time, there was a penalty I thought was not a penalty.
"The lads have done me and the town so proud. It was an outstanding effort from the boys. I am so proud, disappointed but it is now back to the reality of Exeter away."
Wycombe return to League Two action against the Grecians on Tuesday night, before welcoming playoff rivals Portsmouth on Saturday.