same as me i met my husband online for 8 months he finally visits me just once too....and age gap is not a problem as my husband is 16 yrs older than me and after 5 yrs of marriage you can't tell the difference
if you have all the proper docs to support your application you don't need an agency to do it for you of what I keep on reading now in the forum that most of them get a visa with no problem and some of them didn't have an interview at all so just keep on reading here for sure you're in the right track
fiancee or spouse visa is not a problem as long as you have a genuine relationship that's the most important thing on my opinion
