I don't think you have anything to worry about in this situation. To be honest, I would say that this has much less to do with whether God "wants" you to share your notes as it has to do with this admin running the group quite poorly. (To be frank, a group where you have to ask permission to post anything seems a bit strange to me, but I digress.)
I am curious though, what do you mean by wondering whether it's possible to "screw up God's will"? In the sense of God's will being to save you and keep you in the faith, which is what ultimately matters in the end, nothing we do can change that.
I think I understand where you're coming from, though. I myself made some pretty significant decisions in life based on what I thought God wanted me to do, and agonized over other decisions, wondering what the right thing to do was, as it seems you're experiencing now. What ended up happening with me was, after a lot of careful consideration and study, I concluded that the Bible is entirely sufficient for knowing what God's will for our lives is. For example, 2 Timothy 3:16-17 :
16 All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, 17 that the man of God may be complete, equipped for every good work. (emphasis mine)
I don't think that the Bible teaches us to look inside ourselves for feelings or leanings, etc. to figure out what God might want. I know that can probably sound quite incorrect, or even heretical to some people here (in fact, the first time I heard of this way of looking at it, I was in complete shock that anybody could say such a thing, and became quite upset about it. xD) In the end though, I think there is a great freedom in knowing that, as long as it is within the bounds of the teachings of Scripture, anything we do to love and serve our neighbor is pleasing to God. If you'd like to discuss any of that further, feel free to PM me! (Only because part of the rules here include avoiding public theological discussion/debate, so I would rather err on the side of caution as far as that goes.)
At any rate, I will be praying that you would know God's peace in this situation - I found this portion of Psalm 31 to be comforting; hopefully it will be so for you, too. (although the whole thing is quite good as well!)
3 For you are my rock and my fortress;
and for your name's sake you lead me and guide me;
4 you take me out of the net they have hidden for me,
for you are my refuge.
5 Into your hand I commit my spirit;
you have redeemed me, O Lord, faithful God.
6 I hate those who pay regard to worthless idols,
but I trust in the Lord.
7 I will rejoice and be glad in your steadfast love,
because you have seen my affliction;
you have known the distress of my soul,
8 and you have not delivered me into the hand of the enemy;
you have set my feet in a broad place.
- Psalm 31:3-8