I have no idea how exactly gotu kola works, but it sounds similar to my experience with e.g. alcohol. It makes me dizzy and annoyed (and tired), then I tend to feel a bit more energized day after.
Hmm, alcohol doesn't make me annoyed, but it does make me sleepy in 30-60 minutes. I sometimes would use it as sleep aid awhile back for that reason. Doesn't always work either and sometimes I'd need to increase the dosage. Not tired per say, just sleepy, I can have 2-3 shots of vodka and still be up in a good mood doing things. Not annoyed either, more relaxed. Dizzy for sure though.
What was the dosage that you've tried? And have you tried lower doses instead? I've read that with higher doses Gotu Kola might work as a sedative more than an energizer. I've read that about some other supplement, but I don't remember what it was. Could be either Bacopa or Rhodiola, but I doubt I will be using either of those, as Rhodiola might not work with MAOIs (and I definitely need that in my stack).