Mikveh before davvening

There are two aspects to going to the Mikveh: 1. Immersion in accordance with the ruling of Ezra HaSofer, which is done in case there was nocturnal emission, and is therefore very important. 2. Immersion for the sake of additional purity, and for this purpose if you have difficulty in going, you can say Mishnayot from Seder Taharot.