Yes, you need to amend your return. My second oldest, who is now in his second year of the US Army, marked his as being a dependent, without double checking things with me. He was rushing to get his return done. So we have had to file an Amendment for him. Currently, until his Amendment gets approved, he will not get the stimulus check.
So, yes, you, need to amend your return. You may also get back additional on your original refund. My son got back an additional 159 for his.
