Supply Question and in need of encouragement

RedJay

Okay, so DD is 3 months old, and I have been struggling with my supply as of late.  My question is, can I still have a significant effect on my supply?  I finally spent the money and bought a Medela PISA breast pump, made lactation cookies and I am doing everything I know to do.  So, can I still increase my supply or is it too late?  And any encouragement would be awesome because I am awefully close to just giving up and going full formula.  I am tired and worried about all of this!  Thanks for any help!