Help with acoustic guitar barring?

Your guitar neck may have changed shape causing the strings to now be higher above the frets than they used to be. Take your instrument to a guitar shop and ask them to check the neck alignment, and if possible lower the action. If you live in the north, winter is tough on guitars because heating systems dry the air out and drys out the wood in a guitar. The wood shrinks and may warp. Always provide in-case humidification to minimize this (you DO have a case don't you?) Also, change your strings at least once a year. When you change strings, go for light gauge ones - they are under lower tension and barre chords will be easier.