Activities with toddler

I’m 17 weeks pregnant and don’t have a lot of energy at all.. I’m always dragging and I have a 2 year old son. I feel so bad for just sitting around all day watching tv with him and not being really interactive.. what are some things I could do with him around the house that he would enjoy that wouldn’t totally suck me dry! I have a heart condition and connective tissue diseases and almost 18 weeks pregnant so I’m constantly in pain and have 0 energy but I wanna do more with him. I feel like a shitty mom.. help :(