I'm middle too...and hon, YOU are acknowledged and appreciated by your friends and adoptive family...because you are kind, genuine, don't take BS, a peacemaker, strong and "have your own mind"...I thought "being middle" was a curse when I was a teen...I hear you. It gets better.
I am now only oldest, since oldest sibling, my brother passed away at such a young age...younger sister. I've learned patience with myself and others and for the most part, probably nearly the most successful financially and in life as my dear brother; and WAY more than my sister may ever hope to be; she isn't talking to me right now.