I had a habit of retweeting things reading them and then unretweeting when I finished reading all the comments. Now I realize I had good content that I would like to revisit. How can I find all these things I retweeted over the years?
From what I've understood is that after reading a retweet you unretweet it, right? If that is the case, the retweet is no longer available in your tweets but rather to the person you had retweeted from.
Solution: If you want to retrieve those tweets from your profile(if you never unretweeted) or from the original tweet author, use the Twitter advance to filter and find the tweets based on the day it was tweeted, else use the Tweets & replies section to find the tweet if it isn't old. Simple to use -> (https://twitter.com/search-advanced)
Best Solution to your issue moving forward: If you find a tweet that is much interesting and you'd love to read or view it later, use the Bookmark(its icon is next to the like button) click it and it will show you the bookmark option. That way you can easily go to the bookmark section and retrieve it easily.
Again, if you find something interesting and would love to share it with your followers as well as read it at a later time, use the bookmark and retweet icons.
Hope that helps!