You may or may not be mortally sinning, so it’s best to ask your priest about it to help you determine that. Even so, going to Confession each time you do it will probably help break a sinful habit (whether venial or mortal) faster than
without Confession.
Remember that you’re still “unlearning” bad habits (as are we all). It takes time to break bad habits and replace them with new (good) ones, so be firm and consistent, but gentle with yourself when you make a mistake.

The best way to break a bad habit is to just keep chipping away at it; each time you fall, get back up and try again!
You’d probably be surprised how many of us confess the same sins over and over, because each of us has a vice with which we particularly struggle throughout our lives. With God’s grace, we
can overcome them–but that’s not to say it will be easy or that we’ll get it right every single day, every single time. That’s why we have the gift of Confession!
As for Confession, as others have said, it’s very unlikely that your priest will even remember what you said in the Confessional.
In fact, I have a relative who is a Catholic priest and whom we see often, and he was recently hearing (not quite face-to-face, but sort of side-by-side) Confessions at a fairly large retreat my teenaged daughter attended. As luck would have it, she ended up with him as her Confessor (she was embarrassed, but went through it anyway). A week later, at a family gathering, she mentioned the retreat, and he commented that he was there, too, but didn’t see her there. He didn’t even realize he’d heard her Confession (and she wasn’t about to remind him)!
And even if by some chance your priest did remember, he’s aware that some habits are difficult to break and he doesn’t expect you to be perfect overnight. He’s not there to judge you; he’s there to heal you.
Our parish priest has said that one of the things he loves about being a priest is that Confession truly gives him a sense of Fatherhood–that when someone comes to him for Confession, he feels so
proud of them for that! And he loves that he can extend God’s mercy to them and be a part of their healing and reconciliation with God.
I’ve been a practicing Catholic for 15 years, and I still feel anxious about Confession sometimes, I admit. Something that helps me is to remember that the Sacrament of Confession isn’t about shame or judgment, it’s about God’s mercy and love.
Will pray for you!
