Welcome giggles. (Cute name)
You've come to a good place I believe.
I totally understand being worn out after a full day at work. I"m much the same when i have a job.
Can you do any fitness in the mornings before work or during your lunch break?
If not, just do it on the weekend with only walking 30 minutes on workdays.
Its not to hard to find 30 minutes for walking. One really excellent tip that has been doing the rounds for a while is make your travel time to and from work exercise time by getting off the bus sooner and walking the rest of hte way or parking the car further from your train or whatever.
This would probably be the least disruptive way for you to get exercise in. But you have to be honest, if you want to do more fitness, you are going to have to make some effort to change your lifestyle habits. I mean you might have to get up a little earlier, or leave the house a little earlier, or not sit around the lunch room at lunch time.
If you have an hour for lunch, then you have time for fitness then. If you only have half an hour, you don't.
The earlier you can do it in the day the better its going to be for you and you will a lot better in your body too.
On the weekends, there are so many options. I would suggest opting for more recreational forms of exercise that you can do with your husband. Such as joining a bushwalking club or some sort of sporting activity club.
But if its just you on your own, allocate at least an hour and go out swimming, or running/walking, cycling. I mean the possibilities are endless.
Start a diary in the diary section and log your activities and efforts and issues there. We'll all support you.