She doesnít want you finding another partner? That is really an unfortunate request to ask of you and frankly itís extremely disrespectful and simply unfair. I agree with others, being poly/mono as a choice is one thing, but being told Ė ďyouíre not allowed to have anotherĒ, well thatís wrong. I believe poly to already be naturally unbalanced having the addition of a NO you canít find someone as well Ė thatís way too unfair. Granted none of this makes any difference if you are okay with the situation and or if you are willing to take that imbalance (which it sounds like you are not).
One thing Iíve had to face myself with this journey into Poly is the question; Can I be truly alone and be okay with that? There is no way around this simple truth concerning polyamory. So IMO, this boils down to the follow statements that you must be honest with yourself about:
1.Am I completely okay with my spouse/partner/x-friend Ė being intimate emotionally and sexually with another person?
2.Am I okay with being completely alone while my spouse/partner/x-friend is out with their secondary.
3.(specific to men but rarely for ladies) Am I prepared to handle not having nearly as many opportunities to find that special extra someone, and/or am I able to spend a significant amount of time pursing other options (this option is not always available especially for men have naturally busy life schedules potentially due to supporting a family or many other reasons).
I could include many other very important questions to ask yourself and your partner, but I wonít as many of these things are available in the resources that many have posted.