How can I keep from feeling like the third wheel all the time?
Time is a finite resource. Agree with your people how the time is to be spent so it meets people's needs:
- There will be X time set aside to be in trio.
- There will be X time set aside to be in duos.
- There will be X set aside to be ALONE with other people or alone alone. Nobody is joined at the hip.
Then stick to the plan for X weeks. See if it serves you well or needs tweaking.
Without making her feel lonely?
Could be willing to let her feel whatever she feels and let her be responsible for fixing her (lonely.)
If you are spending other times in trio, you could point that you spend THOSE times in trio. Then you could point the the times (BF + GF) spend in duo. And the times (You + GF) spend in duo. It is fair and needed for (BF + YOU) to have time in duo. All of you need time alone too.
If she feels lonely when it is time for (You + BF) duo? It's the price of admission -- everyone has a fair turn. She could spent time with other people. You could appreciate her effort to help create space for (you + BF) alone even though this is hard for her.
If it turns out your personalities do not mix well? Reconsider being together in polyship.
(1 independent) <--> (5 interdependent) <----> (10 dependent)
A super independent (1) person is not going to be a good match with a (10) dependent person. They will feel suffocated with "too much togetherness" if they lean one way to accommodate them. And the other one will feel "lonely/sad/abandoned" if they go lean the other way to accommodate the independent person. Limit reached -- a (9) point gap is too big to bridge well! Nobody is evil -- just incompatible!
The "gap" may not be so bad with a (3) independent and a (5) Interdependent. Or a (5) interdependent and a (7) dependent. The 2 pt gap is easier to take turns with and endure for sake of being together in relative harmony.
Could figure out if this is temporary NRE because it is new or not.
Could figure out what all your personalities rate and if they are compatible long term or not.
You sound like you entered into a polyship KNOWING you have a high needs personality and now come to find you are not up for it.
You could be kind, but firm about your boundaries in this polyship. If the NRE is getting over the top -- could ask for more attention. If it is a limit reached because of mismatched personalities, it is a limit reached. Could decided how to address that or disband.
Galagirl