Struggling with toddler - help

My 20 month old is as sweet as can be when we're with ANYONE else. I recently became a SAHM and I've been struggling so bad. I don't know if it's just a phase, but he whines, cries, screams, or throws tantrums from what seems like when he wakes up until when he goes to bed. He knows enough words to communicate most of his wants and needs. It just seems like anything I suggest, he gets so angry with me. If I suggest we go outside, he says "outside!" but then screams when he has to get his shoes on. If I ask if he wants to eat lunch, he'll say he does but then not want to eat ANY of the options I give him. I just feel like every day is one battle after another and I don't know what to do. I try not to let it get to me, and I generally stay calm and keep my cool, giving time outs when appropriate. But sometimes I do have a weak moment and raise my voice or cry, which just confuses him. It doesn't help my mindset that I'm 15 weeks pregnant and dealing with all those hormones and everything. All I hear all the time is how sweet my kid is, and I know he can be, he just isn't usually to me... I just want to be able to figure things out and enjoy time with my kid because I know not everyone gets the luxury of being able to stay home with them.