Insight: In my opinion it is better to be honest with children than to lie to them. I am not a parent myself yet, however I have always been involved with children's ministries in one way or another. I believe that you can talk to your children about Santa Claus without lying to them. In my understanding the concept of Santa Claus was based on a person who gave gifts to the poor, it then evolved into what it is today. So to explain this concept to them and encourage them to be generous with others especially the poor this time of year I think could be beneficial for your children. As for telling your children there is a Santa and getting your family members to dress up as one is deceitful and many children upon finding out the truth start wondering what else you have lied to them about. It breaks the trust between the parent and the child. Ultimately, it is your decision what you tell your children about the existence of Santa Claus, just be cautious it doesn't damage your relationship in the future.
Insight: Feelings of guilt are typically triggered when we do something wrong, or when we do something that others could perceive as wrong. Other times we feel guilt over the pain that others go through because we were not able to stop them from going through that pain. The best way to know whether the guilt we feel is destructive or constructive is to find the source of it. Once we find the source, if we did something wrong then it is up to us at that moment to make it right. Once we have made it right these feelings of guilt should leave. If they persist, then you need to ask God to take these feelings away or show you if there is anything else you have not dealt with that could still be causing these feelings. Now if the source of the guilt is destructive, meaning that we did not do anything wrong, or we feel guilt over not being able to help everyone all of the time, then we need to ask God to illuminate anything we truly need to fell guilty about and deal with them, and ask God to take any other guilty feelings away, so we can be free.
Insight: No matter what you think God says you are good enough. In fact, you were created in His image and He sent His Son to die on the cross for your sin. My challenge to you is to focus on what God sees in you and not what you think about yourself. I myself have had these thoughts pretty much my entire life and a friend actually gave me some Scriptures which have really helped me, so I am going to share them with you as well.
I strive to help others by being a safe place for others to ask questions and pose issues they face.