Polyamorous problem

Let me start by saying: It's a complicated situation but ugh someone tell me I'm not crazy for feelin the way I do. I am female.

Ive been in this poly relationship with my main gf for about 8 years, together a total of ten. 

When we opened up 8 years ago,  I met another lady and we connected so deeply. She was absolutely ok with me being poly and said they always felt poly them selves and wanted to explore it. We saw each other all the time and got pretty serious and we always agreed that if she saw someone else that she would tell them that she was involved with me. Things seemed ideal. 2 years pass, on and off seeing each other like usual because I traveled for a while.. then she met a girl that tried to break us up, told her she didn't want her talking to me. Thing is, she didn't know that we had been in this relationship for 2 years already. 

She continued to try and break us up and eventually she thought it was over.. but fast forward to today.. 8 years since she met that girl, she still with her and.. we're still seeing each other too.. but her gf thinks we're just friends now.. I know some people will think I'm stupid for stayin in this long distance poly relationship, especially now that she's been with someone else for so long but we have a deep connection.

Somehow we're the ones in the affair now, when we were actually together first. It's just so confusing. And it's gone on so long.