I have a friend who found meditation highly helpful. Cognitively they are someone whose mind amplifies the emotional components of their experience, desirable or not. Tools that allow them to manage this have been helpful to their happiness.
On the other hand, my mind occupies the opposite end of the spectrum, requiring exceptional levels stimulation and novelty to experience any emotion. Practices such as meditation have been borderline damaging to my mental state. But piling on more stimulation - new hobby, new obsession, uncomfortable but fascinating experience - these serve to distract and make life vibrant. Rinse repeat forever.
In your circumstance I would not attempt to achieve closure. Instead I’d try accept that what happened to me in the past will taint what’s happening now. I’d read the books, journal the ways the celebration of them was damaged. Revisit them a few years later to compare the experience. Attempts to force closure have always failed for me. Wallowing in the emotion as means to explore it even more deeply seems to bring more rapid resolution.
Would this work for someone who has much stronger baseline emotions of grief or melancholy? I have no idea because I’m not that person and my opinions about their experience are worthless.
Ultimately in your shoes I would first focus on experimentation designed to test various hypotheses about your own mental tendencies. Where are you flexible versus resistant to change? Which parts of you are resilient and which vulnerable? Seems to me that this would be the fastest way to learn which tools you need to adopt to achieve your goals.
At least that’s how it looks from here. Trapped, as always, inside this particular brain. Good luck.