Resting BPM higher when sitting up?

My resting BPM when I am laying down and calm is 65-85 BPM, but when I am sitting upward at my desk it rarely goes under 90 BPM, is this normal? I'm just worried and I'm not sure if my BPM stays up because I am constantly checking it. I have to lay down after sitting for maybe 1-2 hours because it feels hard to breath. I also usually get a lump in my throat when I am sitting upward. It really seems like anxiety, but of course I'm a little scared.

anyone?

Yes but there is no real,need to keep checking yourself. Ot can go up, down change it is irrelevant. You have health anxiety but im sire you know this ny now and ocd issues as you keep checking, checking and checking as if it will protect you from something, have you tried therapy? And also learn mindfulness breathing exercises they really helo calm the body down nicely. I learned it off you tube actually myself and kept practicing it. First i thought it was a waste  and i couldnt shut my thiught up for the three minutes but one day i got it and it worked and its amazing how it can calm the body down. No thoughts allowed. You do have to give yourself persmission to allow no thoughts during the exercises. It gives you a little break from this, i used to it to lower my blood pressure. That was three years ago. Now when i go into the doctors office i do it so when they take my bp its not High or when anxious and it deciedes to spike. Well worth learning.