Although I don’t currently belong to a Roman parish (I belong to a Melkite Greek Catholic parish), when I miss Divine Liturgy at my parish I attend a Roman Mass. Also, my family is all Roman Catholic, so any changes to the Mass still concern me greatly.
I think I understand your current frustration. I grew up serving as an altar boy at Mass on an almost daily basis. I came to love the prayers as they were worded in the previous English translation, and I felt as though that translation fed and deepend my spiritual life greatly. that being said, I do understand why the changes in translation were made to the Mass (although I’m still torn as to whether or not I like or agree with the changes).
The intention of the current translation was to make the English a “more accurate” reflection of the original Latin. By “more accurate” the translators, according to my understanding, actually mean “more literal.” When you compare the previous English translation with the original Latin you’ll notice that there are a number of things that are seemingly left out. There are other things as well that are paraphrased rather than translated, or they are translated according to the “dynamic equivalency” method of translating rather than doing a literal translation. Dynamic equivalency means that the translators looked at the original text, and instead of translating word for word, they came up with the closest possible idiom that would be understandable to modern English speakers. In many ways this form of translation makes a great deal of sense, and it goes on all the time. For example, in English, when we are feeling overheated we would say, “I am hot.” One can translate that word for word into German as “Ich bin heis,” but to do so implies a great deal of sexual connotations. So the “dynamic equivalent” translation into German from English would be “Mir ist warm.” Word for word it’s not the same thing, but the meaning is the same.
In the Mass one example is the (in)famous “for you and for all/many.” Of course, the “for you and for all” is the previous translation with “…many” being the new. In reality they mean the same thing, if you follow the original meaning as conveyed through the Scriptures, “the many” being the old equivalent of today’s “for all.” They changed it to “for you and for many” in order translate literally and to make the Scriptural connection more explicit.
In the “Lord I am not worthy…” the reason for the change, again, was to be more literal, and to make the Scriptural reference more explicit.
I hope this helps some.