Feeling a little guilty

Tonight I'm feeling a little guilty because I should be working and I'm not! My husband and I own a business and we sort of share our job. It's a retail business (a health food store, in a Mall) and open every day. I usually work around 35-40 hours a week in the store and because he has severe Arthritis, he works less hours in the store, and takes care of the money management end of the business at home. Eight weeks ago he had hip replacement surgery on his right hip. It was very successful and he has made a good recovery due to the fact that he has followed Doctor's and Therapist orders and so is now walking pretty well with just his walking cane to help his balance (he will continue to need that for a few more weeks). While he was not working in the store at all during the past eight weeks, I have had to work more hours than usual. Luckily we have two good employees at the store who have also been very good during this period. I do not drive, and Richard was not allowed to drive for six weeks so I had to rely on our staff or neighbours for ride's to work etc. Well the past couple of weeks I began to get a lot of aches and pains in my lower back, and have been experiencing a lot of fatigue, not sleeping that well etc. I think the stress and extra work has finally caught up with me! Yesterday Richard went into work in the store for a couple of hours so that I could rest up a little. He felt fine afterwards, no pains or aches! Today I was supposed to work from 1pm to 9pm, but this morning I just felt so tired, then began to feel a little light headed and just....out of sorts....is the only way I can describe it. So when he offered to work for me this afternoon, I let him, thinking that I would go in at 5pm instead. This afternoon I lay down on the bed just to see if I could nap for a little while. Usually I don't nap because it takes me too long to get to sleep, and then when I wake up I feel too groggy like I haven't had enough sleep....but today...I fell asleep, only to be awakened by the phone ringing! It was Richard offering to work the rest of the shift....till 9pm! At first I protested saying he would be over doing it all at once.......but then finally I gave in and said okay he could do it! Now I'm feeling guilty and lazy! Should I have gone into work? I think I should. I have not taken advantage of the day off and caught up on any housework or anything around the house, instead here I sit at the computer writing about it! I have the best husband and I never tell him that enough....and yes, I'm guilty of that too!