Some days WILL be harder than others

When the going gets tough, I often quit.  I had a tough day yesterday breastfeeding because I had an irregular schedule and could only pump twice instead of three times.  I didn't manage my time well and didn't speak up when I needed to leave and pump.  I just kept my mouth shut and worried and got anxious.
Rather than see whatever is happening as a tough blip in the road, I see it as a behemoth problem and decide that the only solution is to quit.  It's such an automatic reaction, I completely blow things out of proportion and I have a hard time seeing the bigger picture.  At least in that moment.  I actually considered quitting breastfeeding and pumping yesterday because I had one tough day.
Sometimes I have to talk myself down, sometimes another person talks me down, but it is definitely a pattern and I am wondering if I have some underlying beliefs that are driving this compulsion. 

• Irrational Belief #1: It's too hard.
• IB #2: I will never be able to do this.
• IB #3: I can't handle it.
• IB #4: I am a bad person because I can't handle this.
• IB #5: If it's hard I might as well quit.

Ooh, IB #4 really hit home for me, really drew some deep emotion out of me.  When I can't do something or it's hard, I immediately think it's a major flaw with me.  It's not just how life is for everyone, it's specific to me.  I just suck.
Let me go ahead and reframe these now:

• Rational Belief #1: It's hard now but it will get easier. OR Some days will be harder than others.
• RB #2: I may never be great at this but I will get better. OR It's hard now but it will get easier.
• RB #3: I can handle it.  It's hard/tough but I can handle it.
• RB #4: You are a good person whether you are good at something or not. OR You are a good person even if you suck at something.  OR I am a good person and I can handle it.
• RB #5: If it's hard you can keep trying. OR It's hard now but it will get easier. FOLLOWED BY If it doesn't get easier, you can decide to stop.
• RB #6: It's okay to suck at things.  Everyone does sometimes.

I read somewhere that "gifted" children often get easily frustrated because things come easily to them generally so if they struggle with something, they will get defeated very quickly.  I think this is me.  Normal eating is the first thing I've really tried to work on and it is HARD.  It's the only thing I've never thought about quitting, though :)