if you say "独学" to Chinese people ,I think few people can understand it at once, some one maybe coule guess the meanning when they have seen the Character.
“己学”="ji xue" ,it is in common with "独学"。
you can say "zi xue,自学(self-study)" in Chinese,it is from the phrase of "zi ji xue xi,自己学习"。"zi xue" is in common use .
I wish my reply can help you, and have a fun in learnning Chinese.