Why do i feel this way?

i have been in karate for about 3 months now and it doesn't feel like i'm learning much... i can tell i am but always my father and older brother like to play fight and mess around.... for some reason i always lose so it makes me feel like i'm not getting better.... i know i have improved cause i'm quicker and my reflexes are quicker but they still don't match up to them... i need some advice from others, did you feel this way when you started learning?