This is my dreams too it like we are in the same boat .it has been in my bucket-list for too long. What is keeping me is still finances and I have been drawing plans on how to execute and it yet to click. I think we can start with keeping aside some money either weekly or monthly.
Then we can then have it in a fixed deposit that we might not need to get it out for about 12 months or more at least we might get something substantial to visit some countries and then continue the cycle again to save to visit more countries.
Taking a loan might be another idea but I don't know if the banks will like to finance this it just for one to approach them and finally maybe asking for international donor agencies to help finance the trip if we are in luck we can find one to sponsor us.