Need help toddler tantrums

My son is currently 19 months and I'm a 34 weeks pregnant stay at home mom and my son has the worst tantrums when he is bored which seems like all the time. We only have 1 vehicle which my husband needs for work and I cant take the bus we are to far out that it take 2 hours to get anywhere. He hates all his toys and never plays with new ones for long I've tried every toy, doesnt like tv. We only have a patio which we play with a water table and stuff but he is bored of that too. There are some places to walk which I take him everyday but he wants out of the stroller and to walk himself which I dont mind doing but hes getting bored of that too and try's to go on the road and loses it when he can't and then on weekends we go out lots with him but whenever hes in the car seat he cries and when we have to do stuff like groceries and he can't run around he throws tantrums. Feel like I'm losing my mind.