Rocks don't swim very well

Ouch, my shoulder is hurting right now. I'm still struggling in the pool because my pull has issues. Coach Michael told me to practice tomorrow and do 1000 yards alternating between kicking and swimming. I was very frustrated in the pool today - I actually teared up a little (luckily no one can distinguish tears from pool water). Looks like I will need to put in at least 4 swim practices a week until race day. I don't know what else I can do. I know I can get this, just that I need more time and patience which I sometimes feel I am running out of. I swear I must have been a rock in my former life, because that is how I feel in the water.