If your horse time is anything like my horse time (absolute zen!), then take up her offer. I was working part time and going to college full time, and I burned out in two months. I didn't have horses, or a hobby that could bring me back to my happy place at the time. I might still be in college if I did. Even if it is one day a week, or right before school or after work, just those couple of hours to breathe everything horse, it will be worth it. If you are not taking lessons, at least you can still touch and smell them, and get your happy time.
I hate my job some days, but I will happily go and muck some stalls for free before work (which is totally harder labor, but definitely not a mental task) if it just means being around the horses for an hour.
Think of it not as a failure but as a success in how not to do it.
Don't look in a horses mouth for a gift.