Why cant I touch the screen on the phone

if your touch screen is unresponsive, there are a few things that could be going wrong.

1) most commonly, your digitizer is failing. The digitizer is the touch processing panel under your glass. you can try to get a new one and see if this fixes your issue.

2) this is less common, but will cost less to fix, which would be a software bug. run a factory reset through your recovery mode on you device to see if it fixes your touch.,

3) board level failure. the least common to cause a straight lack of touch, but the board may be having issues. without excessive training in Microsoldering, as well as access to the schematics for your device, you will be unable to repair this, and will have to replace the motherboard with one from another device instead.