Old Bugbears

PLAYING at the 54th Berks & Bucks Congress, where I have been placed in the Challengers, which is both Fide rated and ECF graded.
In round one I lost to a junior (1684 Fide/162 ECF) after turning down two draw offers, and in round two beat a player with neither a rating nor a grade.
The common theme of both of today's games, from my perspective, is that of playing too quickly and hugely overestimating my position for most of the time.
I keep telling myself to correct these bugbears, especially the former, which, in theory, should be easily corrected, but they persist.
The round-one debacle has cost me 16 rating points, knocking my "live" rating down to 1959.