ghq is rough for me but a few things help: room temp syringe, upper glutes (no pinch needed), add extra bac water to dilute, and massage the site after.
Psyllium working on the diarrhea and managing it while also adding cagri is useful clinical data for the OP dealing with the acute GI episode. The watery diarrhea at 2mg that improved gradually is the typical course - it usually isn't persistent at the same severity. How long did the episode last before you could manage it and what dose are you currently on?
the side effects at the current dose usually being worst in the first few weeks at that level is the practical context for deciding whether to push through or step back - 'normal and usually go away' is accurate on the population level, but 'shouldn't be in physical pain' is the right individual threshold. there's no virtue in enduring severe GI effects when a dose reduction and slower titration exist
Upping to 2mg and immediately getting violently sick is the too-fast-too-soon response. The timing of the dose jump and the GI reaction happening that night is almost certainly the culprit. Dropping back to 1mg and waiting another 4-6 weeks before trying 2mg again is the path most people take after a response like that.