Hi Nacho, speaking from someone who's husband is an Indian Yogi, I agree with Mike. Mike is right about the exruciating pain. Do not force yourself! You'll tear cartilage and believe me, I tore mine and you don't want to do that. You have to treat your body with RESPECT and GENTLY.
It takes YEARS for yogis to be able to do the asanas. They practice daily and gently coach the body to stretch into the positions. Please slow down.