Help please

So about 2 months ago I found a lump just under my nipple, I've got a hospital appointment in 10 days to see what it could be, but since then I've been extremely exhausted and I've had quite a few nose bleeds which I've never gotten before. Has anyone had this before? If it is cancer I really don't know what to do, I'm only 21, I don't want this to make a massive impact on my life I'm not ready for. I really need help and advice.