i hope you are coming to terms with the reality of your current situation and are feeling better as the time passes.
i can empathize with you and your emotional pain, as a result of how your scorpio partner decided to handle the situation, you described. based on the fact, he did not reply to your text, writing a letter with the context of a self- characterization, may prove to be counterproductive.
also, delivering the letter at his work, may further create more misconceptions of you. silence speaks volumes and indifference can be quite effective, let him miss you.
i was involved with a scoprpio man for 3 years and i also, as a result of 2 conversations, was in the same predicament as you find yourself today, tormented and distressed. though, i wanted to contact him, i did not. after 3 weeks, he called me and continued to call. i did not answer his calls. it will be 2 yrs. ago in october. I have a deep love for this man, but i love myself deeper.
when someone claims to love and care about you, clearly this behavior is not consistent with those feelings. as you love this man deeply, so will you love another, that will not leave you, without closure and subject you to such deep pain.
while he cowardly did not end your relationship with words, his absence is clear to the effect, that it has ended.
i know you will be fine, it will be a challenge to move onward and require much strength and time. though in the end, if he does contact you, you will have the choice to allow him back in your life or not, thus, restoring your mystery.
stay well and all the best to you during this difficult time.