You’re not sure about your last confession:
If your last confession wasn’t very good, you might want to be careful about receiving the Holy Eucharist. When I say “wasn’t good”, I mean, if you willfully withheld a mortal sin, you’ve not been restored in grace. You need to see a priest, rectify the problem then you can joyfully receive Jesus. However, if you are scared of venial sins, even unconfessed ones, you needn’t stay away from Jesus. When you pray, God forgives your venial sins.
Even though the Church exhorts you to confess them in order that your sense of sin might be stronger causing you to avoid graver offenses with a little more ease. However, venial sins cannot deter one from receiving.