Since you have come from the Anglican tradition several good guides are at you finger tips. If you are British, there is The English Hymnal of 1906. If you are in the US there is, of course, The Hymnal 1940. Each of these books contains many hymns that are quite Catholic in content. Indeed, many of them have been borrowed from the Catholic tradition. A study of these would provide invaluable guidance for anyone wishing to compose new hymns. A good modern Catholic hymnal would be the Lumen Christi Hymnal, which, in glaring contrast to most current Catholic hymnals, has excellent translations and language. Another invaluable source would be the translations of Latin and Greek hymns by John Mason Neale. The Collected Hymns, Sequences, and Carols of John Mason Neale is available as a reprint. Look it up on the internet and order it from Amazon. Another scholar and translator of historic hymnody is the Catholic Edward Caswall. Too, there are the translations of office hymns, not to mention several original hymns, by St John Henry Newman. Any of these sources would be invaluable exemplars as to form and content - and, of supreme importance, a language which expresses itself in a sacred grammatical style.

As you have stated, hymnody in the Catholic Church has quite different functions than it does in the Anglican tradition - though nowadays there is considerable overlap. Historically, hymns in the Latin west were restricted to the daily offices. Only since Vatican II have they been allowed a prominent role in the mass. In this, their function is not terribly different from Anglican usage. It is important that they be appropriate to season and to the lectionary of the day. Or, they may be meditations on the Sacraments or the spiritual life. As well, they may extol the virtues of given saints, etc. They should at all costs be objective treatments of aspects of theology, avoiding any subjective personal or communal experience. (You want them to be divinely oriented - not about subjective experience.) Ordinarily, hymns at mass consist of a processional, an offertory (when there is no anthem), a communion, and often a dismissal.

While this usage is all but universal in the US it should be borne in mind that the use of hymns has for the most part supplanted the far more appropriate and ancient Propers of the mass. These consist in a set of antiphons and responsories that are assigned to every Sunday and Holy Day. They may be found in the Graduale Romanum, which you can order from GIA. An English version of this Graduale is Bruce Ford's The American Gradual, which is available from Lulu. Some now, notably our gifted forum member Kathy, have written hymns that are poetic interpretations of these propers, particularly the processional introit. You might want to follow this example for some of your hymns. At any rate the propers might well suggest thematic subjects as inspiration for new hymns. And, such as these would be quite desirable for liturgical use.

Be sure to share some of your work with us!

Since you have come from the Anglican world I must ask if you are associated with the Ordinariate of the Chair of St Peter, established by HF Benedict for those of Anglican heritage who are allowed to maintain their historic liturgical, musical, and spiritual traditions. Is there an Ordinariate parish anywhere near you?

Anna, I like this hymn. Thanks for sharing.
One note on engraving: words that are split over multiple notes should still use hyphens between syllables rather than extender lines, which should only come at the end of a word. (mm. 10,12,14.) "pro-tec-tion" rather than "pro-tec____tion"; the slurs indicate the note grouping visually.

Thanks :) It's such a funny thing... there are scores that I have poured over for HOURS, finally committed to print (mind you, I was doing test prints and reviewing physical copies during the editing process) and immediately noticed mistakes after printing 20 copies.

Hi PolskaPiano and thanks so much for your kind welcome!

I wonder whether perhaps EBENEZER (Williams), also known as TON-Y-BOTEL, might work. It is as somber as it gets---but then, so many of us are feeling thus.

https://hymnary.org/search?qu=TON+Y+BOTEL

I enjoyed the text- although I have to say that due to the clever wordplay in verse four, my chuckling would have made it hard to sing!