Help! What did I do? I've taken Iodine and it burns...

So, I ordered Lugol’s iodine a few weeks ago and just received it in the mail. I wanted to use it right away, but I wasn’t sure how…I thought applying 3 drops under my tongue would suffice. I wasn’t able to come up with much of anything after doing an online search of other people administering it this way, but as I was impatient I just assumed it would be okay because I thought I had heard of it before.

It burns like satan. What have I done? Should I be afraid?