I need to bring up the feelings of being excluded to my new friend group
Why do you think you're being excluded?
I'm concerned if they are excluding me or not, I get treated really well by them, but it may be temporary.
I'm sorry you're having such doubts like this, and you are doing the right thing by telling them straight away. They and yourself will appreciate all the honesty and it can only result in a great relationship. If you kept holding onto these feelings they will break the friend group apart.
Really? It's really sad for us to break up...
You don't really have to break up. Just let them know your feeling and if they are good friends, they will understand.