try to ask her..and know the reason of her different behavior...u said she is not bahaving good... may be she is worried,tensed or very bzy with some work so she is not giving u time properly..but if she loves u from heart then she will be with u all life

"Love isn't finding a perfect person. It's seeing an imperfect person perfectly."
"Being deeply loved by someone gives you strength, while loving someone deeply gives you courage."