hamstring/groin pull

[alap]

I injured myself slightly yesterday.
Small waves, lots of chop after the windstorm. Not a good conditions really(not a single crawler) - still had great time for 3 hours.
Caught a wave, set the bottom turn, sitting low, feet probably 4' apart, leaning on the paddle.
Then I dont know what really happened, probably bumped in one of those chop bumps, or into the piece of seaweed, but lost a balance, fought to recover, unloaded my back (left, I am goofy) foot and it slipped into the water. Because I still was going fast (or loaded on the paddle?), the left foot didn't  go under the water straight, and the right foot firmly planted on the deck was still traveling with the board. I made a bit of a spread, plus with back foot in the water all the weight is on the front one, and as I said sitting low (knee bent full 90 degrees), - felt sharp pain in the groin/hamstring area.
Was able to climb the board, even caught another one (standing tall, not bending), walked to the car. Changing wetsuit and taking off booties was most uncomfortable.
Its certainly better now after ibuprofen and ice. but still some discomfort. Had read on the net about my symptomps, I d think it is a groin (abductor muscle) - I can lay on the back, straighten my leg all the way and lift it (I understand with hamstring pull this wouldn't happen). Sits up, squats are uncomfortable. Still much better, so I am contemplating if I should go today (two days of vacation left) and just take it easy, or just skip the day alltogether.

Did something like this happen to anyone?

Whats the exercise to strengthen this muscle?