I think a lot of people here mistake anxiety with bad thoughts.
I know a lot of people who just simply cannot smoke pot, yet they can drink way more than me.
Bad thoughts or generally depression seems to manifest itself in "anxiety". Focusing too much on your heart rate isn't anxiety, it's basically a normal reaction to cannabis. Most people do not grow up in a culture which is suitable to cannabis consumption, thus initially and very ignorantly compare it to alcohol. This is done either conciously, or subconciously.
I'm quite bothered by the "just stop" attitude here. Of course, if you do not like cannabis and think that you are not suitable to cannabis consumption, stopping is the best idea. But when anxiety comes in the picture, I think people should just stand back a minute and think about WHY they react so badly to cannabis.
When you "trip out" you basically overreact to your heightened senses. Feeling your heartbeat, or thinking about it for the first time can force you to ask yourself, "am I ok?". Yes, you are ok, but isn't it just a little bit odd that you are realizing your heartbeat now? Or do you really, truly give two fucks about how you come across to other people?
I mean, you do know just who you are... don't you? Well... do you?
Adressing the problem is important. Letting go is the answer.
Remembering can be hard. Forgetting sometimes harder.
I always forget to remember.
And remember to forget.
Switching strains is just a practical way out. Cheap way outs, shouldn't be a part of cannabis culture. It works for many, but I'm opposed to it in principle.