What's a believable lie for how I got a deep cut (stitches)?

Long story short, I have a hypertrophic scar from an old wound that required stitches at the time but was untreated. I despise the scar and am too self conscious about it to live with it any longer. Unfortunately, I am a broke college student and cannot afford any of the pricey scar removal treatments. I've already tried a million OTC treatments and am at my wit's end. I read that doctors will sometimes cut out hypertrophic scars and stitch up the wounds into neat little lines. I am contemplating cutting the scar out myself and then heading to the ER to receive my stitches. I am afraid, however, of being put on suicide watch or something else annoying if I tell them I did the injury to myself. I have no desire to self-harm, only to be rid of this scar. I also need an excuse to tell my parents for why I needed stitches. Does anyone have any believable stories for how I would get a gaping wound on my arm? Please only respond if you have suggestions, I do not want to be told that this is a "bad idea". It's not perfect but it's the only option that I have. I've had this scar for 5 years, I can't have people asking me about it anymore (it was originally a self-harm scar and I hate when people figure that out). I just want to leave behind that chapter of my past and stop being reminded of it. Thank you!