facing issues with keyboard and a little bit glitch with both screen and keyboard too

sir,

i have an iphone 6, 64GB, Model No. A1549, 1GB RAM DDR3, Dual-core 1.4 GHz Typhoon (ARM v8-based) running on latest iOS 11.4.1

From past few days sir i am encountering a glitch i guess, when I am typing the keyboard is misbehaving... like if I am typing p or any other 1st row keys then it will automatically pick up suggested words from the suggestion box. and after a lot of hard work the key get to work but if i click on it the second time again same thing happens. same goes with the dial pad... keys 1,2,3 are not working due to that reason i am not able to reset my iphone. and due to this my screen is getting slow too.

To solve this problem i have tried -

1. tried to shut down my phone and then turn on again

2. tried to restart my phone which was the pretty much basic thing i have done firstly

3. and was trying to reset my iphone too, but sure to keys 1,2,3 keys not working I am not able to put my passcode

please help me sir!!!! I am in crisis!!!