Hey there! This usually happens when your account violates YouTube's Community Guidelines, if you feel your account was taken down in error, you can appeal the decision here: https://yt.be/help/7epT . If that's not the case, mind sharing your channel's URL so we can look into it?
We review appeals 24/7 and will reply as soon as we can, you should hear back via email shortly! Also, if we find that your video did not violate our Community Guidelines, we'll reinstate it and remove the strike from your channel.