Proxy wars is defined as unconventional warfare waged upon enemy through covert means usually involving splinter militant groups. Since Kashmir is not Indian territory, (whole worlds recognizes it as disputed land, which rightfully belongs to Pakistan) then how could any struggle in Kashmir, direct or indirect, supported by Pakistan, can be called a proxy war? If anything, it is Pakistanis defending their own territory, trying to drive out the invaders. Now if we had employed the same tactics in say, Aasam, or Indian Punjab, then you'd be right in saying Pakistan started it.
Kashmir is not yours, get over it.