Feeling like I can't help

So...today my car broke down...my boyfriend is trying to figure out what is wrong with it and fix it. In the meantime, he is letting me borrow one of his cars. He is currently working on fixing the water heater in his house, so all day he has been dealing with fixing things. I have felt like I was in the way most of the afternoon, until he asked me to go pick up something at the store (I was finally able to help). I also cooked dinner, which he normally does, but I thought I should give him a break from that, especially since he is working on my car and I did not end up working today.
So, the hot water is off, and I went to the bathroom, forgetting this...when I washed my hands, apparently, since the sink was not turned all the way to cold, it started spraying in the basement. My son ran upstairs to tell me...
I feel really bad...I tend to want to help with things (or, at least, not make them worse), but I also feel in the way and incompetent...

It might not feel like it to you, but it does seem like you did help out as much as you could, especially while under the stress of having your car breaking down. I'd think that your boyfriend appreciated what you were able to do, even if it doesn't seem like that much to you. Sometimes just small things to help can make an impact. And about you forgetting about the hot water being off, everyone makes slip-ups and can be forgetful at times.

You did help a lot in my opinion and that was a mistake that you couldn't know about or maybe forgot. Don't beat yourself up, you are trying your best and this is who you are, you shouldn't be ashamed.