First off, don't beat yourself up about spending 10 years equivocating. I put conversion off for 25 years before I got the hint (applied with a sledgehammer) and got into RCIA. Long story and I've told it a couple of times before, but if you want to know, tell me and I'll send you a link.
Secondly, don't get into a panic about what you call "belief shift." It even happens to the saints. St. Teresa of Avila (not just a saint, but a Doctor of the Church) wrote of her struggle during a 20-year long "period of dryness" (her words) in her faith. In fact, you might want to look into having her as your confirmation saint if you don't already have someone in mind. No urgency there, though, because you have plenty of time yet to make that decision.
Spiritual dryness is not easy to go through, and I certainly don't enjoy it when it happens to me. I don't know about anyone else, but I have to "stubborn" my way through it. I have to recognize it for what it is--a spiritual attack--and make a conscious decision not to let it affect me. It does, though. Prayer gets harder to do. Temptations get harder to resist. Doing what I know I should (prayer, rosary, Bible study and devotionals, Confession, yes, even attending Mass) gets harder for me. I just have to tell myself "Too bad, I'm doing [whatever it is I should be doing] anyway" because I know that this feeling will eventually pass. It does that every time.
I will also say that it's amazing what a difference the Sacrament of Reconciliation makes. It's still one of the most difficult things for me to do. I'm naturally an introvert and some very unpleasant life experiences have taught me to keep my true feelings and thoughts buried very deep. It's hard to go before someone for whom I have great respect and reveal my screw-ups. But you know what? The feeling of joy and freedom I have when I leave is indescribable and more than makes up for any trepidation I had going into the confessional.
If you haven't gone to confession before, again, don't worry. Father won't hold that against you. On the contrary, he'll very kindly lead you through the process and will rejoice at your desire for reconciliation. I will say, though, that if you think you need more than a few minutes, your fellow parishoners will be very appreciative if you call the office and make an appointment rather than just getting in the line. Chances are, though, that the actual Sacrament will be done in less time than you think. God is amazing that way.