I accidentally ate noodle soup the first night of Passover, I had it in the microwave before Passover and saw it and started to eat it without thinking late that night because I’m a diabetic. I feel horrible, is there anything I can do, I prayed for forgiveness
This was a serious sin, for two reasons. First of all we are not allowed to keep any chometz in our possession over Passover, and we must rid our home and possession of anything of the five grains before Passover. Secondly, it was a sin to actually eat it on Passover, which is a particularly serious sin.
Fortunately though, H-shem in his unending kindness gave us a way to atone for our sins, and to repent to Him. The teshuva process is a three-step process. The first step is to have remorse, and to genuinely feel bad that we violated his commandment. (This would apply for both of the transgressions separately, the not getting rid of the chometz and the eating it). The second step is to confess the sin to H-shem (in private) by saying, “H-shem, I transgressed you commandments, by not getting rid of my chometz, last year ,and by eating chometz on Passover, and I regret what I did”. The third step is to accept upon yourself to correct the situation and make Passover correctly this year. This will need a bit of learning and studying the various laws and requirements, and you should buy a book to help yourself learn the various laws, regarding cleaning the house and the kitchen, kosherizing the kitchen for Passover, searching and getting rid of the chometz, and what products may and may not be eaten on Passover. I am attaching some articles written on the subject, which may be helpful to you.