Help with bp

My bp has been up. If I lay down it's ok sys in 130s die in 50s but once I stand up its 140something over 90 something or higher always. I went to hospital like my dr told me and they checked it for an hour but ONLY while I was laying even tho I told them it goes up when I stand. But they told me it looked good and sent me home and said if it goes over 140/90 to come back like they did before. It's 115/97 now but I don't want to go back for them to lay me down and check it and tell me it's ok. I feel stupid and they make me feel like I'm making it up even tho I showed them ova of my bp monitor. The even had the nerves to tell me I didn't kno how to check it.  What do you ladies think is it to high now?  What should I do?