Artifactos- Given practice you will most definitely get better! And you're fortunate enough to have someone to help instruct you, which is great. When I started training for my first sprint tri I couldn't swim an entire lap without having to stop, the year after that I swam across a lake & back (2miles). Just keep at it & you'll get more comfortable and things will come together. It's crazy how much confidence you have in the water effects your performance.