Ok.. I just want to note that I advised against LSTing your first grow esp since you only have one plant. I agree with mallo that you will learn a ton by just watching and seeing how it grows naturally the first time. That being said, your LST looked perfect to me. I cant see what you have it tied to but you can pull the strings tighter as it grows to get it to 90 degrees. Its prob best to go slow with it anyway.
But now that you have untied it, I'm not sure what to tell you to do except probably to choose a method and stick to it. Tying and then untying is prob a bad idea. The plant sends its growing hormones to different parts of itself depending on where it "thinks" its top is. You might be confusing it by switching back and forth if a plant can be "confused".
Anyway, its prob best to leave it untied if it straightened back out fairly quickly and just let her grow naturally. But yes, a pic would help