SAHM bored and not sure what to do with excess time

Morgan
Sorry for the long post!! 
I've been a part time SAHM for the past few years. I care for my step-daughter every other week and now that she is in school, it's every other week plus every Tuesday and Thursday when she is finished with preschool at 11. So I have quite a few days and times all to myself. 
In the past, I went to school technically full time but it was only a few hours a week and the rest was online so I would only be away from my step daughter a few hours a day while she napped at my moms. I finished my Associate's degree and was going to get my degree in nursing but we decided last semester I was going to stop going to school because my fiancé and I wanted to try for a baby this year so this is the first time that I do nothing except stay at home. 
I'm getting stir crazy and don't know what to do with my time. When DD is in school, I workout and/or visit my mom or friends and I also workout with my fiancé when he gets home a few times a week to try and keep busy and get out of the house. I did have a part time babysitting job so I could take DD with me and she could have play dates but that is coming to an end in two weeks and I know I'm gonna be bored to tears not leaving the house much at that point. 
I help out at the school when they need and we go to the library once a week but that's all I can think of to keep busy. It's winter here so I can't go on walks or bike rides or go to the park like I would like to, so I'm not sure what else to do.
Btw- I'm 15 weeks pregnant and having lightheadedness and fainting so I'm supposed to see a cardiologist soon for that so I do not want to get another part-time job because of those reasons so that's not an option either :(
Any tips from other stay at home moms/wives? What does y'all schedule look like? 
Thanks for anything in advance! 👍🏼💕