Is it normal that I think I look putrid...?

putrid = decaying or rotting and emitting a fetid smell

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but yeah we all have our good days and bad days. If you have acne, that seems to be a major factor in confidence - whenever I have a lot of spots I feel my self esteem drop. I look at myself and think "I'd look so much better without these ugly marks on my face".

It's all a frame of mind though. You can talk yourself into feeling better about your image, it just takes focus and discipline to only consider the best aspects of your appearance. Confidence is attractive. If you maintain the illusion of confidence, eventually you won't be pretending.