Are you still harming yourself? If not and you're talking about the same few scars that might show on your forearms I don't think they will not be particularly noticeable and I'll tell you why: a lot of people are so consumed by their own personal concerns they either won't notice or they will see without really noticing and anyone who asks or comments -- if their intent is rude or their manner is to put you down -- they aren't worth engaging in conversation anyway. If wearing long sleeves won't be remarkable because the weather makes them inappropriate; I'd be inclined to mix it up with long sleeves and 3/4 sleeves until I got the emotional climate of my new work -- then if it felt like a good place I'd probably wear short and 3/4 sleeves if the temperature called for it. I always want to err on the side of compassion for someone who shows they have had a struggle.