Pregnancy pains

I need advice and help :(  idk what's going on with me or my body... I'm 16 weeks (17 weeks in Friday)  okay... I can't lay in my back I get pains.. I lay in my left or right ride to long my legs go numb. I'm so light headed sitting or standing.. My chest hurts so bad like I almost can't breath.. I have lots of pressure when I pee.. Tmi but sex hurts.. After it almost feels like I'm paralyzed.. My doctor says it's just my body changing.. And my discharge I wipe after peeing and there is so much it's like I pee'd again....  The pressure when peein got just started tonight..