Sentence 2 is correct. If you have come to a specific decision about something, you say that you have "made up your mind/made your mind up".
A "mind map", I believe, is similar to what is also called brainstorming, where you have a large sheet of paper with a subject in the middle and then you write all kinds of different ideas around it.
Remember that you must capitalise the word "I". See amendments above.
I would also probably remove the comma and replace it with "and" or a dash, or even make them 2 different sentences. However, there are a lot of discussions on here about the use of commas so for now, I have left your original comma in place.