I think we all have times like this....I felt the same at the end of my pregnancy. I have a two year old and it didn't matter how many times I told her I was tired and I couldn't play she didn't understand and kept pushing regardless until I would finally lose it at her. I felt bad more times than I care to count. All I could do was give her a cuddle and tell her I loved her and move on. I was shipping her off to MIL's more than I should have been because I just could not cope with her at the very end. And she knew I was physically incapable of chasing her around so that just made her play up even worse
It has got better since I had the baby and we are just now getting that closeness back. We seemed to lose it there for a little while but now I have the energy to take care of her and play with her instead of palming her off onto her father at every opportunity things are definitely improving. I'm sure it will for you too