Is low BP the cause of problems

I've posted a few questions about my worries about having a heart problem, the answers seem to unanimously be I have nothing wrong. But yet symptoms remain (chest discomfort, burning, tiredness, feeling washed out sometimes). More recently I have been seeking help for anxiety. I find this hard to accept, but I do accept that many doctors telling me I'm ok and it's stress are perhaps correct. But I also can't help but worry that I'm trying to convince myself it's in my mind.

I've noticed something now though, something I mentioned to one doctor who brushed the remark off. But I think it might be relevant.  

My BP seems to get quite low sometimes, on another post I said this was after exercise and the response suggested this is normal. But last night I did no exercise, I did have 2 cans of beer and I felt quite unwell. Felt extremely tired and drained and like I might pass out easily (I didn't pass out). My BP was 86/61, pulse was about 100. If I layer down my BP was about 100/77 and I felt better, soon as I stood upmthe BP would go back down. We had ordered a meal tomb delivered, I ate most of this and just had to go to bed. My BP didn't go down anymore after I ate the meal, if anything I felt sightly better.

I think I may have some sort of problem with my body controlling BP correctly. Usually the only thing that helps the chest discomfort is either to lay down and go to sleep or to go out and have a walk or go on my bike.

Could the 11 months of worries about my heart actually be down to BP?