Swiming to get peace of mind, or peace of mind to be able to swim??

I love swimming because it is a great sport that is friendly enough to keep you away from injuries most of the times. However, I also love swimming because of the mental relief I get from it.

The question that I haven’t been able to answer is weather I get peace of mind from the pool, or If I try to get peace of mind to be able to swim. Last night work and personal problems left me exhausted, Today my swimming simply sucked!!