I feel like I'm losing it

How do I stop being so negative I can only ever focus on my faults and negatives things about myself I do it so much I honestly get surprised when someone tells me that they think I’m cute or handsome because it’s impossible for me to see the same person they see.

I’m finding it harder and harder to care about the world around me, things don’t interest me here lately and I just don’t understand why I should continue.