As Sancte Joseph said, the Gloria should be sung (or at least recited) on each Sunday except during Advent and Lent. Is there any chance that the celebrant could have made an innocent mistake? I myself know of one priest who is quite old and hasn’t been very well in recent years - I don’t recall that he ever forgot about the Gloria, but he often gets confused during Mass, and if he ever forgets anything, it is plainly obvious that it wasn’t intentional. So, ordinarily it would be an abuse to omit the Gloria, but just consider that it may have been a genuine mistake.
Regarding the Eucharistic Prayer, Redemptionis Sacramentum says:
[51.] Only those Eucharistic Prayers are to be used which are found in the Roman Missal or are legitimately approved by the Apostolic See, and according to the manner and the terms set forth by it. “It is not to be tolerated that some Priests take upon themselves the right to compose their own Eucharistic Prayers” or to change the same texts approved by the Church, or to introduce others composed by private individuals.
It sounds like your priest composed his own Eucharistic Prayer. Was he trying to make the language more “politically correct” or was there extensive ad-libbing? Either way, yes, it is forbidden to change the words of the Mass texts:
[59.] The reprobated practice by which Priests, Deacons or the faithful here and there alter or vary at will the texts of the Sacred Liturgy that they are charged to pronounce, must cease. For in doing thus, they render the celebration of the Sacred Liturgy unstable, and not infrequently distort the authentic meaning of the Liturgy.
- The faithful have a right to have the liturgy celebrated according to the laws, texts and rubrics set forth by the Church. A priest who changes the Mass on his own initiative denies the faithful this right. So, again, unless your priest is perhaps unwell, lost his place in the E.P. and panicked leading to short-term ad-libbing (which I have seen happen), a grave abuse did indeed occur.