Outcasted

So we were 3 ppl me nad my 2 friends lets call them A and B. Last year we were all going out togather talking about everything etc. But this year after july they r cutting me off like no reason i am still me there isnt any change on me. There is a change in A like ahe call B everyday so they got closer amd now they r going out without me sharing everything with eachother and me later. i wanna let them go but i care about them so much that it hurts. So what shoul i do about it? Let them go or act like i donr care about their unknown going outs?