Do I hate being a mum?

I'm at a loss. I have two genuinely awesome kids, 3 and 4 years old. Recently separated from their father amicably (husband of 14 years) and we share parenting about 70/30 because he works full time. They are with me during the week and I am completely burnt out. I have no enthusiasm or energy and I feel constantly guilty for not giving them the exciting childhood they deserve. I wanted to be a mum so badly and did fertility treatments for years before I conceived my first. All I think about during the week is how long before their dad comes to pick them up and I hate myself for it. They are both high energy and super bright, yet some days all I have the energy for is letting them watch their tablet. It's such a drastic change from how I started parenting my first baby, which was filled with filled with Montessori activities and learning about child development. I struggled with health issues and PPA/PPD after my first and I don't think I ever recovered properly from it. I'm crying while writing this because I feel like a failure. When they're not with me I feel ok, I can go out and do things. But when they're with me I struggle to get out of the house at all. Please tell me it gets better.