Stress

I am 25 weeks almost 26 weeks pregnant with a baby boy, I got told they couldn’t see half of his face or half of his heart in my last sono they didn’t schedule me for another one until the 28th of this month which is forever away and on top of that I am having relationship issues with the father. So long story short I am STRESSED out. I’m more worried about the heart thing then any thing else that’s happening. What is the best thing to do for stress? I don’t want to make things worse at all.