Dante's poem looks back on a time when the speaker nearly ended their own life, and then turns toward survival. The title says it plainly: the speaker is glad they didn't. The "you" in the poem is someone who made them feel scared, fragile and undeserving, and whose words stuck like something the speaker gripped too tightly to let go of. Judging by the lines, that person left a lasting darkness, "finger tips" that once held the speaker down.
The mood shifts as the poem goes on. It begins heavy and numb, with the speaker admitting they once wished they had given up. Then the tone becomes quieter and more hopeful. The speaker now craves their future, looks forward to talking with a partner, and notes that their chest no longer hurts before sleep. The short closing lines, all beginning "I want," feel like a person claiming their own life, ending with open hands ready to love and be loved.