Caapi has the strongest effects and Blue Lotus and passionflower have weaker effects than caapi. Marigold, mullein and peppermint are not psychoactive. All of the plants you have bought are frequently used as changa additives, if someone bought these things all together I would assume they are doing so so that they could make changa but if you did not buy these plants so you could make changa what was/were your reason(s) for buying these plants?

Mullein has healing effects on the lungs while caapi is a hallucinogenic MAOI with effects on its own such as euphoria. Blue lotus is a very mild sedative.

A lot of this is experimental. Do you know the use for each of these? It's always good to know what each of them do and was used for in the past. Also, if you aren't sure if it is a placebo or real fear, then lower your smoke dosage next time, and give yourself a couple of hours in a secluded area at home, and quietly observe how your mind and body react. My cat first experimented with an entheogen known as amanita muscaria March of 2010. He tried it a few times, felt spooky and made up his mind that all the negative forum postings were correct and that amanita was not a good entheogen to fool with. Then, about 8 months later after exploring microdoses of caapi in gelcap form, he began to be curious about the amanita muscaria again. He began microdosing with the mushroom and has been able to work through the spookiness and fear.

If you don't remember but one thing about all entheogens its that they will not only heal your body , but your mind. This means that they will bring up things that we all suppress, so that we can work through them. There are many painful things that we've all buried deep down, even if you've had the best life, there are still those parts that you're not too comfortable with to put it lightly.

Here's my recommendation and maybe it will help you,
1. Get to know your entheogens intimately by researching the history and the use, where it came from, how did it get its name, etc.
2. Be sure to have a trusted friend or relative nearby at all times. It's best if you have someone who is familiar with the effects of the entheogen and who will be able to reassure you calmly if you start getting anxious.
3. Set your intention. If you're just smoking for a high or to get a few kicks, then you may get more than you bargained for. Some entheogens are less forgiving for foolishness than others...
4. Choose a quiet and peaceful area for your setting.
5. Microdose for an extended period of time, but be sure that you know all the health risks involved especially if you're taking other medications or consuming alcoholic beverages. Microdosing means that you take small amounts that you can barely feel and then work up from those dosage amounts in tiny increments slowly. Try microdosing on each particular herb or plant for a period of a week or two, to really get an intimate experience with it before moving on the next. Some of the entheogens can be smoked directly, extracted into crystals for vaporizing, and boiled and brewed into a tea. Each particular method will give you a totally different experience in some cases. It's good to have a solid experience base of each particular entheogen.

It seems that whatever dosage you smoked is a microdose, because you weren't sure if it was placebo or a real effect. Maybe continue experimenting with that, and make sure you have someone around you can trust incase you feel too fearful afterwards. Hope this helps