Good news... That IS starting your journey.
Okay, I know, that’s super sucky in the good news department.
It’s just also true. Because in order to learn to effectively manage triggers & stressors? You actually have to be experiencing triggers and stressors, and then be experiencing a symptomatic reaction to them, in order to learn/practice your management tools.
The very first time I did that? I was super crazy lucky to be around people for whom this was old hat & the entire process was much looked upon as a game, rather than as something wrong to avoid. To “win” the game I had to (or have to) get back under control faster & better, and recover faster and better, each time I was triggered. <<< It’s a skill set that requires practice. If I’m having 25 panic attacks in a day? I am going to barely be losing any time to them, because I’m practicing the ever loving hell outta my skill set. At my best? My heart can just barely skip or rapid fire a few beats as my adrenaline system
rockets 
skyward... only to get yanked back down to earth by the collar & told to sit-stay. Total elapsed time? Just a few seconds. COMPARED to when I haven’t had a panic attack in several years? <low whistle> There goes not only my entire day... but the next several days in “hangover” from it.
***
As far as grounding skills, my best methods are usually a combo of blowing off stress / burning off the chemical concoction swirling around in my blood (read: exercise) combined with sensory tricks, like hot/cold/hot/cold showers, a cold drink in a hot shower, or hot drink in a cold shower... or movement through space, (which combines exercise & sensory stuff)...particularly? Complicated movement I have to be paying attention to, to avoid biting it. Think things like gravity sports (surfing, snowboarding, springboard diving, etc.), or gymnastics, or sparring with a partner, although practicing forms by myself can help as well if I’m looking for more of a meditative bent, rather than a reactionary one.
Breathing is neither of those 2 things (blowing off stress/burning off chems NOR sensory in nature)... which is why I said my best methods are only “usually” in one or both of those. Shooting is how I really master my breathing... because you can’t hit what you’re aiming at if your breath is all over the place, or you’ve got the shakes, or a heart that makes jackrabbits look lazy. Dropping into the same measured breathing I use for shooting, also drops my heartrate like a rock, and steadies the rest of my reactions.
^^^ I’ve tried a lot of methods that I was SURE were going to be amazing, and hell maybe they are... that I just cannot “reach for” or even remember... when everyhting is kicking off. So -after a long bout of stubbornness- have learned to simply bin them. No matter how good an idea? It’s still just an idea. What matters is when the rubber meets the road.