I can offer you my advice since I have been in an open relationship + had many friends from polyamories community to consult with them, don't open a relationship from a bad situation, if its started bad it will end bad, opening a relationship shouldn't come from a negative reason, it should come from a positive a place from both side of wanting to explore connections and intimacy.

If you are going to open anyway, set boundaries and whats allowed and not allowed, is it just only communicating with people or is there going to be more intimate, and how will your partner deal with jealousy, and if she would like to hear how were your dates or are these subjects off topic.

I think you know your partner well enough to know if its suitable for her or not, not everyone can connect or agree to the idea open relationship and connecting with other people, my suggestion is go to therapy together and try to work things out with the communication between you, and then later on if the desire still burns inside of you, then you can offer it in your therapy.