what is wrong with me? 😩

Yesterday I had some energy I did laundry and some cleaning. But today I'm exhausted I haven't been this tired since the first trimester! I slept 9-10 hrs last night just to take a 4 hr nap. I haven't gotten off the couch all day because I'm just so exhausted. There is so much pressure down there and the heartburn is ridiculous, haven't had it the entire pregnancy until 2 days ago.  36+ 3 weeks.