Since you are a beginner, please do not be discouraged by suggestions. Sometimes "criticism" in the sense of literary critique gets confused in our hearts with criticism, meaning "you (personally) are not good enough." One of the problems in English, and beauties of good poetry is that words can mean more than one thing! So let's begin there.
Your first line suggests to me that you want to make a toast! But to what?! Your struggles? That doesn't fit with the rest of the poem, does it?
Your next line tells me you struggled a little to get a rhyme. Many people will tell you not to worry about rhyme as a beginner and personally I think that is usually poor advice; but maybe not. Concentrate on one thing at a time. Either rhyme or meter. Once you get one down, bring the other into perspective Then remember that it isn't the rhyme OR the meter that makes a piece poetry, but the words and meanings behind the words and the ideas that are suggested by them which are enhanced BY things like rhyme, meter, assonance, dissonance, alliteration, etc., etc. Good poetry shouldn't be hard to read and tongues shouldn't stumble over the words UNLESS there is a specific purpose for deliberately making that happen. Remember, almost all great poetry was meant to be read aloud!
Back to the point. What suggests the struggle to rhyme is the phrase "fails to last." Except "fail" means does not succeed and suggests that lasting would be a success. "Does not" or 'never" would be closer to what I take your meaning to be, although then you have meter issues to clean up. This is hard, but that's why not everyone is a poet! Easier to pick apart than to write!
What all does the word "pardon" imply? Judicial pardon for crimes? Or just "Ahem, pardon me." Those leap to my mind first, but what you mean is forgiveness of childish wrongs and parental excesses in discipline, perhaps. You are neither a judge nor someone interrupting another nor have you accidentally bumped into someone where you might normally use the word "pardon." You see, the dictionary is a necessary but not adequate tool for finding synonyms. We have to ask ourselves what connotations each word has or we wind up making huge mistakes. Remember when Jimmy Carter went to Poland and used the dictionary to say in Polish "America lusts after you" Instead of "loves you?" Or when JFK went to Berlin and said "I am a jelly donut" instead of "I, too, am from Berlin?"
"Even still..." You mean, I think, to say "nevertheless" or basically, none of that changes my love for you. But remember every word in a good poem counts for something, so why say "even still" rather than something else? What are the alternative meanings and connotations of "even" and "still?" What does it remind you of? Does nothing else fit better?
(An aside: "MomMa" has three m's.)
Likewise "adorn." Once upon a time people might say they adorned themselves with everyday clothing. Now they tend only to say that when they are trying to be very elegant. We might say "they adorned him with an ornate and royal hat," but not he was adorned with a hat. Or else we talk about adorning something else, as in decorating -- a Christmas tree is adorned with ornaments or even a doll with the latest wardrobe, but only theater moms would adorn their sons.
Okay, I haven't gone through the whole poem with you, though I could; but I don't want to overwhelm you. And there are some good things to say about it too.
Above everything else, it is a loving present for your son. He is not likely to be caring about the words, but about his mother, and you have told him what he craves hearing: that you love him in spite of any past conflicts and are proud of what he has made of himself and his family. You have shared your memories of his childhood and your feelings about what it has meant. You have opened yourself to him, and I am sure he will appreciate that very much. As such your poem will accomplish a great deal and mean more than sending him Shakespearean sonnets.
It doesn't take perfection in something to make it wonderful and meaningful. In fact long ago I discovered that to get something fro 90% to 95% of perfect takes the same amount of time and effort it would take me to get six other things from 60% to 90%. Writing great poetry means struggling to get past the 95% and takes not just genius but almost always some really hard work, although serendipity helps, too. If you want to practice poetry, go ahead. Remember those who stop trying to walk -- or ride a bike -- after they fall down a few times never learn to walk or ride. But just as learning to play the piano, it takes practice. For that matter, so does being a better person. Even Toscanini was not a perfect musician, but imagine if he didn't constantly practice! Mother Teresa mentioned that it takes practice to love selflessly, too.
A happy and blessed new year to you!