The 3rd trimester

Idk if it's because I'm in the 3rd trimester , that I'm feeling really bad but for the last two days if I'm taking a shower or just standing period I feel like I'm going to pass out , I've been feeling really bad and I'm trying to avoid going to the hospital for nothing , I've been resting but it seems like nothing is working my feet have swelled up so bad it hurts to walk 😖 my pregnancy has been smooth this whole time until now . Idk what to do 🤒