To me, it seems obvious that both you and your ex still love each other. But.... is it the same kind of love you have with your current girlfriend? Did your love morph from a true partner to friendship? Did hers? And your love for your current gf, is it the kind that will last as it is, or will it morph as well to something different.
Take this with a grain of salt if you want. I put these questions out there to get you thinking, and with both your heart and brain, not just one or the other. Whatever you decide is not going to be easy on anybody involved, especially you.
I also phrased these questions so as not to question if you love one girl more than the other, just what type of love is actually present. My wife and mine's love for each other ended up morphing from true partnership to friendship (mainly because of trust issues arrising indirectly and unknowingly from my being trans). If anything we actually love each other more now than before, and our relationship is stronger as a result. It's just not a true partnership anymore and is now friendship, but bff's.

Look into yourself and try to see the ties that bind, and figure out what kind of ties those are. Then you should be able to make the decision you need to. If it helps, calm yourself through basic meditation techniques so you don't become over emotional in your search.
I hope it helps