Carnt conceive because of my weight!

I'm struggling ! My husband and I have been trying to conceive for 5 months now. That may not seem so long as I know many woman have been trying for years but the pain each month of that single line feels just as bad ! The doctor says I am not conceiving bescuse of my weight. I weight 82kg and my bmi is 30.1 . My doctor told me I need to be between the bmi of 18 -25 . I'm on my feet at work for 9 hours a day so I don't feel like coming home and excersising :( does anybody have any tips and tricks to help me out ? I'm letting my husband and my only dream in life down because I love food ! Please help me anything would be useful ! Thank you