It is better to prevent the gynecomastia signs in the first place. If you are already showing symptoms then the horse has already bolted so to speak. The dopamine agonists (cabergoline, bromocriptine and pramipexole) only do good for men so you shouldn't be concerned with taking them for prevention.
If your cabergoline was in liquid form then that would be the reason it didn't work. Cabergoline is unstable in liquid form and should be bought only in tablet form.
The dose of bromocriptine you are on is sufficient but since there is an immediate problem you can try upping the dose. If you can tolerate it you can increase your dose: try 3.75mg for two days, then go up to 5mg.
Another anti-prolactin drug that many on this forum like is pramipexole. It is available from Researchstop at a good price. It is good to have things like this on-hand in case of situations like yours.