There is no question that it is a workout
. So you've probably got some muscle soreness which is really normal.
As for foreplay, etc. being smoother, that comes with practice and patience more than anything else. Helps to be with someone who truly cares about you, too.
Insecurities are also rather normal as you are making yourself vulnerable. It's not like the movies, so don't try to compare it. You're doing fine.