While Godfollower’s statements would be absolutely correct if you had no idea whatsoever that the sins you were committing were mortal (in other words, if your ignorance was invincible), that does not appear to be the case. It seems that you really suspected that those sins just might be mortal, but did not take the time to find out for sure before you committed them. According to the Catholic Church, this is culpable ignorance, and does not excuse you from mortal sin. Here are the pertaining sections of the Catechism:
"1790 A human being must always obey the certain judgment of his conscience. If he were deliberately to act against it, he would condemn himself. Yet it can happen that moral conscience remains in ignorance and makes erroneous judgments about acts to be performed or already committed.
1791 This ignorance can often be imputed to personal responsibility. This is the case when a man "takes little trouble to find out what is true and good, or when conscience is by degrees almost blinded through the habit of committing sin.“59 In such cases, the person is culpable for the evil he commits.”
Jimmy Akin also wrote a great post about the three conditions for mortal sin. I’ve included a pertinent section, but I would definitely recommend reading the whole thing–I certainly found it enlightening! (Here’s the link: jimmyakin.org/2006/12/assessing_morta.html )
“You sometimes read about a person needing to have “complete knowledge” of the moral character of the act. I think this is misleading because it can make it sound like if you aren’t a thoroughly catechized moral theologian who has thoroughly studied a situation and has all the relevant facts at his fingertips then there is no mortal sin.
Suppose I’m a poorly-catechized ordinary guy who’s out hunting in the woods and I see a shape in the forrest in front of me that I think might be a man, but it might also be a deer. I am not excused from mortal sin if I shoot at it anyway, even though I didn’t know for certain whether I was objectively shooting at a human being or not.
I thus prefer to speak in terms of “adequate knowledge” of the moral character of the act. There are a lot of things that we can know in an intuitive or incomplete way and still be mortally responsible for them. If this were not the case then St. Paul would never have been able to speak in the terms he did in Romans 1 about pagans who “do not have the Law” (i.e., the Torah) and yet are gravely responsible to God for their actions.”
Try to get to confession as soon as you can. Ask your priest if he can hear your confession tomorrow before or after Mass–I’ve done this many times, and the priests have always been more than happy to help! I’ll be praying for you!