Need motivation

So I started a weight loss program through the Beach Body on Demand app. I was doing great for the first few days but now I just feel tired, sore and all I want to do is relax and watch tv. I’m currently on maternity leave with my 2 month old baby so I’m home all day. Other than taking my son to and from school. I feel so guilty for relaxing and not getting a workout in, but I’m tired. I’m at my heaviest weight I have ever been which has completely destroyed my self esteem, I feel like none of my clothes look good on me anymore, I no longer feel pretty and to top it all off my son tells me I’m fat and my husband weighs less than me. I know he’s probably disappointed at how I look now as when we first started dating I was extremely fit, I worked out daily, I looked after myself. Now I just feel like a slob. What makes matters worse is 2 years ago we went through a little hiccup in our relationship, he was constantly talking to a girl whom was flirting with him and sending him inappropriate photos, it took me so long to convince him to stop talking to her, I threatened to leave him and that’s when he stopped. Unfortunately that caused a little bit of depression and trust issues to linger for me. Anyway I’m not sure where I’m getting with that part haha. Well the other day I creeped on this girls Instagram and she had posted her before and after photos of her weight loss journey. She went from having a body like mine to having an amazing body. He still follows her on Instagram so he obviously saw her photos. I feel so unattractive and I know if I quit with the “rest” days and just get off my butt I can achieve the body I want and used to have. But I just can’t get the motivation