I wonder what would have happened if you were to have been completely honest with the mentor? Yelling seems a little extreme and unnecessary...
I know what you mean though. I was drawing pictures for this old guy who has a hobbie of making story books. I had finished the first half of the pictures and was paid (way over paid, the old guy is rich and bored let's just say. 100 dollars for each ****ty picture!) and then I was supposed to contact him when I finished the rest. Well, I couldn't even find it within myself to start the rest let alone call him. Not because I didn't want to work on it, simply because now it was something that I must do! Also I just got judgmental vibes from him, there was no way I could call him.. So I procrastinated forever and never got back to him. He's my mother's tennis friend, and apparently he called me a devil child or something to her after that. I don't blame him, I took 200 dollars and never finished the job. He contact my mom recently and tried to be all friendly about the situation, expecting I would call him to finish it I guess. No way I will be able to do that.
Same thing with this old recipe book my grandmother gave me to re-type, as it's falling apart. I started, I got well into it, but eventually It became one of those things I thought about all day and never did out of fear of, something?? I never got back to her either. My grandma and I are like strangers so you could basically say it's like doing something for a stranger, except one that you're expected to hug and treat well. I feel so guilty about both of these things! That recipe book was ancient and her favorite... I still have it and I'm going to finish it if it kills me, or the guilt will