Anybody have tips on how to make therapy/coaching more helpful?

Hi,

I have an issue where the person I like with is constantly getting annoyed by things I do (or don't do), for example recently my car was in the garage for almost a week and I normally do the shopping, but as I go in the car I was putting it off until I got the car back as they didn't give me a set time so it could always be the next day. This then resulted in then confronting me about why I had been lazy and not done it or asked them for help with it. This then resulted in 2 problems.

1. I started to shutdown as discussions like this have happened a lot and a lot and I don't like upsetting or annoying people, but this then only annoys them further as they view it more as childish and unfair as they can't have discussions about things like that.

2. They want me to give a specific reason for why I did it, so in this case not doing the shopping or asking for help, and I don't have an answer as I don't know, all I could say is I was waiting for the car to be fixed, but that just got them angry as they "don't want excuses" just reasons so it can be fixed. 

The issue though is honestly I don't know what to say or how to sort it as I was just waiting for the car as to me that made sense until we ran out of something we needed, but they don't like anything running out and prefer things to constantly be in stock. This then creates issues with getting help though as I've been to therapy and coaching and neither has helped a great deal as they put the emphasis on you to identify the issue, but other than knowing I'm bad at remembering things I don't know why I do it. 

Has anybody else had experience with this and found a good way to word or to get get help? or found a way to sort it themselves. At this point people are just viewing me as selfish and not caring about them, when at the very least I don't want to be like that, but its hard to sort as I don't actively think "Oh I could do that to help them, nah I don't care" I just don't think about things like that unless asked to help or actively seeing somebody who needs help with something. 

They are now pushing me to seek help for my "motivation, priorities, manners, coping mechanics and development of life skills" but as I've already tried therapy and coaching as they haven't seemed to help I don't know what to do. I'm more than willing to accept I am just inherently selfish and crap at life skills, but especially when combined with being autistic I just don't even know where to start.