About Senna's Build Path...

So my teammates said I was useless last game I played because I didn't build damage. In another game my team said I was useless for building damage, saying I was support and should never build damage. I'm really confused on how I should build her. Should I lean more towards getting the most out of my E, Ult, and Q via utility build (athenes, ardent)? or Should I build for damage and pray I can carry that way?

My thing is like... well my last game was a lost cause either way. JG and top both got hella stomped. But as a support I don't feel like it's necessary for me to build damage when 4 other player son my team are doing just that. So what do you guys think? Is there any time when I should be taking one over the other aside from being somehow the only AD champ on my team or something?

ty in advance :)

ps: yes she's pretty damn op but if you can't beat em, join em. please try not to complain about her in that way here. not going for a debate on something we all know already .lol