Horrible neck posture, lowered head

I'm not extremely tall, only 6'3 but I stand out a bit in my country or at least I recognize if somebody is taller than me. I feel like this and the fact I have just recently split with my girlfriend of 3 years who was about 5 feet tall I hold my head really low to be closer to other people. I even realized I'm looking downward most of the time as well and looking at a 0 degree angle in front of me feels weird. Anybody else had similar experiences? Normally my neck should be a straight line not the shape of the letter ' r ' right? Is there any workout or something to fix this or I just "have to hold" my head in the right place from now on?