Horrific heart burn

Hi Guys

Mum 11 weeks pregnant, the morning sickness seems to be easing off but has now been replaced with horrific heart burn.  I have been eating small meals, avoiding spicy and fatty foods, sleeping sitting up, drinking some milk and taking over the counter medicine. But non of it is working, it’s so painful and draining. I can’t cope with this for another 6 months!! 

Any advice or tips would be very much appreciated  

thanks G