1 John 1:9 - "If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness."
1 John 2:1 - "My dear children, I write this to you so that you will not sin. But if anybody does sin, we have one who speaks to the Father in our defense—Jesus Christ, the Righteous One."
Bro, it sounds like Satan's talking some major crap to you in your mind right now. If you haven't confessed your sin to God, take it to Him and ask for His forgiveness. He's faithful to forgive if we ask Him to. If you're going through thoughts in your mind feeling like He won't forgive you, that's just Satan trying to fill your mind with lies. The Bible says he's a liar and the father of it, and we know he talked crap to Jesus, so we can expect no less for us. But what did Jesus do? He stood in the Word of God and told Satan to get behind Him. As one who has accepted Christ, you are a child of God, and you don't have to be distressed over Satan's lies.
As far as the thing of plotting in your mind about telling them it wasn't upside down... This is my opinion, and I don't know exactly how far you went with it, but I don't think you sinned there. Jesus said that it's not what goes into the mouth that defiles a man, but what comes out that defiles a man (Matthew 15:11). Remember, it's not a sin to be tempted; even Jesus was tempted, and we know He didn't sin.
Basically what it comes down to is that Satan knows our weakest points. He knows how he can drive us up the wall. Ultimately his objective is to destroy us, but if he can't do that he's going to do all he can to frustrate us in our walk with the Lord. But these frustrations don't come from the One who has called us (Galatians 5:8). Jesus' blood was powerful enough to take all our sins, even when we don't feel like it. If you've sinned, confess your sins to God, but believe that He's forgiven you -- not because you were good, but because Jesus' blood covers our sins.
Galatians 5:1 - "Stand fast therefore in the liberty by which Christ has made us free,
and do not be entangled again with a yoke of bondage."
Sometimes I go through the same kind of stuff myself. And I've had my share of B.S. tickets, too.
So if you need to talk to someone who's been there, my PM box is open.