Anxiety during sex

So I’m brand new to sex, but obviously I like it. I have social anxiety though (depression and bipolar too) and only have had it drunk, and I’m still anxious and awkward. Like what do you do during sex? What am I supposed to be doing? Am I not doing something I’m supposed to be? I know it’s supposed to come natural and I do what’s natural but this voice in my head always says something else. Or nags me. Makes me think I’m failing. I just let them take the lead and follow or do what they say or feels natural. Still voices haunt me. I don’t watch porn and I know it’s not like porn so I won’t. But I don’t know anything. Any advice? People say just to get over it. Don’t worry. But it isn’t that easy when you have mental illness and anxiety. You can’t just get over it or not let it get to you. You can try but it doesn’t work for me. So I feel that makes me bad in bed. I can’t stop overthinking everything. Any advice or anyone with similar experiences? I’d much appreciate it