Sleeping posture

I’m currently 33 weeks pregnant. Having trouble of sleeping posture as I have been having some lower back aches but when I consult my doctor about it she told me it’s normal and all I have to do is sleep in my left side. But it’s been a month and it’s getting worst. Also I can’t sleep comfortably it seem like I’m having insomnia. Any advise on my sleeping posture? And how to sleep comfortably? I know having a frequent urine is normal but it’s always in the middle of the night and I can’t get enough sleep Everyday. Please do give me advise as I’m first being a mom here.