Yeah, don't bargain would be my advice. Bargaining has threads of desperation to it, and DMT is the type of molecule to "smell blood in the water." Have respect, have reverence, but stay sturdy and stay strong. The other thing about it is that it's going to give you what it gives you, so there's really no bargaining in the first place.i have a similar mantra that i've come to repeat a few times right before as well. i take some intentional breaths saying to myself as i exhale "exhale doubt, fear and negativity" and as i inhale, "breathe in love, gratitude and humility" and similar to your "trust" mantra upon inhale i say "thank you" while taking the hit. these practices have kindof evolved over time but now after my few rough experiences i almost feel these statements are me negotiating with the spice to please be nice to me. i liken it to approaching a friends pet german shephard who's usually a kind and lovable dog but one time you accidentally moved to quickly around him and he bit you pretty good. so now you operate a bit differently around them and always approach hands out, moving slowly, and showing respect.
When I say stay sturdy and strong what I mean is be with whatever you happen to feel. Breathe with it. Invite it. "Oh, fear, hey there and welcome to this present moment, now sit down and shut up please." This doesn't mean that you don't feel any fear, but instead that it has no say about your action and your sense of being. It doesn't become a second thought. Trust that you can do that. It's allowed to be, just like any feeling you would normally welcome, they just get to sit in the peanut gallery while you get into the space.
Also note that in my mantras, they are very particular to me, allowing all else to be whatever it may be. This will be a good skill to cultivate.
You may not have done anything... that's the real weird part. The space just... changes over time for many. This is why I talk so much about doubts regarding how long people will stick with it. Keep showing gratitude, keep showing reverence, but strap in a bit more than you used to. You may start to get more that you don't really know what to do with, as though the space is being more open with you about itself.but with the spice i never felt i did anything to trigger being bit (at least as far i can tell) so i found myself almost feeling kindof hurt and betrayed so i say these mantras less to myself to center and prepare but more to the spice to say like "see, i'm showing you gratitude and treating this ceremony with respect so please don't hurt me"..
Surrender, my friend, surrender.i spent that first experience resisting very intensely as my identity was being ripped away from me.