You are a patint of depression
but picking scabs, pulling hair, biting nails edges are more of signs of anxiety neurosis
Anyway I think you are taking regular medicine for depression if not then please make sure you take them because lately studies have proven Depression to be a Neurotoxin.
Obviously a paradox bacause a toxin must be a substance but researcher put that strange term just to impress how much damaging the lack of treament could be.
Next time when you go to your physician get yourself evaluated for Anxiety neurosis and ensure you get a treament for that.
Your second query about bruise
like appearance- Bandaid is a very poor dressing. may be you kept it applied there for more then a day and the wound has got macerated and became bruiselike- red and oozing.
I would suggest get a standard dressing of yor wound.