Welcome, Erica. As it is said here, glad you are here but sorry you have to be.
First, foremost, and above all else -- OXYGEN is what you want for stopping attacks. It's the life-changer. You will have a lot less need for other abortive meds (such as triptans or Nurtec) when you use O2.
Then there's the vitamin D3 regimen -- the best, safest preventive.
An energy shot (such as 5-Hour Energy) or drink (such as Red Bull) at the first sign of an attack can reduce its severity or even sometimes abort the attack. There are reasons why the shots are preferred (more caffeine, easier to get down fast). Don't know how this fits with your heart situation.
You can read about all of those things, and some more, in this post: https://clusterbusters.org/forums/topic/6213-basic-non-busting-information/
You might want to consider busting. Click on the "New Users..." wording in the blue banner at the top of each page for busting basics. The same information you would get when you click there is at the very end of the post I linked you to.