Am I able to train and learn nin-jitsu on my own?

its very hard too from my expierence especially when you have no teacher to know wether your even training right... there is no local schools were i live either....I take karate but im desperate to quit that and just find a ninjitsu school. It is also extremely hard trying to master the 18 skills. Im traning in tai-jutsu (hand to hand combat) by taking karate but im not sure if karate is the appropriate way to train tai-jutsu. I also know some of kuji-in and am studying chi-kung with chi techniques and stuff and train for kinesis. I try to read books and stuff without drills since there are no partners i have to train with. This is just really hard and stressful.... How would you reccomend for me to learn? how can I do this without a sensai? am I doing this right? And another thing... how the heck is a 14 year old like me guna find a horse to ride for the art of horsemans ship? I dont have many martial arts weapon stuff either for all those nin jutsu weapon drills either...