I will attempt a poetic correction :o)

Love requires tolerance, trust and tenacity,
Be, of love, a little more careful than of anything else,
When the one we love is lost.
Our most bitter tears are called for by the memory
Of the hours when we loved, not enough.

As Marcus said you would never talk this way in day to day conversation because poetry is an artistic play on words to express feeling. But as long as you can learn to differentiate between poetry and everyday speech as you are learning, then you'll be fine.
I write poetry too and it's tricky even for some natives so well done on your attempt!
Beautiful words by the way :o)

Love requires tolerance, trust and tenacity. Be a little more careful of love than of anything else.
When we lose one we love, our bitterest tears (or, bitter tears) are called for by the memory of hours when we did not love well enough.

Your original rendering sounded very poetic but it would come across poorly in speech or day to day language. Even as it stands this sounds very formal. But a good thought. Keep up the good work!