Well, I may be new to your tumblr, but for what it’s worth I’ve never noticed even a typo either :P And you’re plenty smart too! But I guess we all tend to be hyperaware of our flaws and much too hard on ourselves (I know I do).
I know what you mean, though - I didn’t have much of an idea of what to expect from the IELTS either, and that made me even more nervous. One thing to keep in mind is that the focus of the test is really on fluency and the ability to communicate, so there’s no formal grammar stuff. Also, you mentioned your accent in your previous post - mine is pretty atrocious, so I was VERY nervous about the spoken part of the test. Yet for some bizarre reason, I actually did better in the spoken section than in the written one. I guess it didn’t help that the topic of my written essay was sports - I know next to nothing about them and that limited what I could say. But even then, I guess that this shows that what they look for in the interview is mostly an ability to understand the questions asked and make yourself understood. If I managed to do that and score well despite my *dreadful* spoken English, I’m pretty sure anyone can :P Good luck, and let us know how it goes!
PS: Thank you so much for your comment. I’ll reply properly there, but I wanted you to know it meant a lot to me <3