That does sound suspiciously like anaphylaxis. Not sure from your post what you did, but it does not sound like you went to hospital. The only remotely safe option then , once there was any issues with breathing or facial swelling was to call an ambulance, there is no possible way to predict if it will get worse or better, but given worse could be dead in that situation not going straight to an emergency department is dangerous.
I would strongly suggest not to ever test it to see if it was a true allergic response , just assume it is and avoid it forever. If a doctor wanted to do a test dose to see if you were truly allergic they would only ever consider doing that in a controlled environment with resuscitation equipment close by, and use a 1/10 or 1/100th dose. Trying it again at home is too high risk, given how severe the possible outcomes could be, even if you had an epipen at hand. It is possible to get this done by an allergy specialist but given the drug is not released yet my guess is they would be very reluctant to do the test with a grey sourced unapproved peptide. And in general they will only test if the reaction was not anaphylaxis, but some less extreme reaction.
I have not seen numbers for drug allergies to cagri, but they happen for all the other GLP peptides, I would expect the drug itself is almost certainly the culprit rather than a contaminant or the bac, given that allergic reactions to peptides are fairly common, even if mostly they are just injection site reactions.
At least elora is now out so you have a better if a bit dearer option instead of cagri.