SW that is a great time given the weather and the field. It's over 105 in the south, I am guessing that Sac is much cooler
. It might be that having such a competitive field elevated your run a bit more than you realized. (Unless you found it demoralizing - which doesn't seem like you).
A 7:10 pace??? OMG I can only dream of such a thing. I believe you can
sub-20, but it will take a lot of dedication and maybe a couple less races as you focus on the train regiment.
As handcycle2005 suggests, you might think about adding the intervals into your routine. (You might already be doing them, and I am just not aware of it, however).
Or you could keep on just having fun