Having trouble loading 12,227 photos onto my Mac?

I've had iPhones for years and have always transferred all the information from previous phones onto the newer editions, so over the years I've accumulated an execessive amount of photos which I need to totally clear as I'm going overseas and need the space on my phone for new photos. Everytime I connect my phone to iTunes, iPhoto no longer opens (if it does it freezes and shuts itself down), so I can't import through that direction. Does anyone know how I can get them either on to the computer or onto a separate hard drive (either is fine) so that I can keep my photos somewhere while freeing up the space? My iPhone is up to date with software etc, is a 64gb model but it's just not doing it! Thanks in advance for your help!