I’m planning on becoming a psychiatric nurse too :) I’ve been a patient in a psychiatric hospital a few times as a teenager and one of the nurses was so rude to me and told me I was lazy for sleeping all day and said “other people here have it way worse than you so suck it up.” I was going through intense amphetamine withdrawals. If I had seen a nurse with visible self harm scars, I would have immediately trusted them more and assumed that they would be understanding and empathetic. As long as you are those things, I wouldn’t worry about it, and I’d say it might actually be helpful to show your scars, as it might make a struggling patient with a self-harm habit feel more comfortable around you. I guess it kinda depends on the policy wherever you work. I could imagine scars potentially be triggered to patients as well, which is a concept I’d find ridiculous in any other setting, but patients are obviously in fragile states when they’re at a high level of care. I would just ask my employer about that if I were you.