MacBook Air Keyboard & Trackpad not working

Hello,

I bought a Macbook Air (13 inch) last year. Last week, I opened it up and entered my password as usual, but when I logged in and tried to actually USE the laptop, I found that the keyboard and trackpad were very very, laggy, as in I would type something and I would sit and wait a solid ten seconds for it to actually work. I used a plug-in and bluetooth mouse and they both worked fine, however the trackpad did not.

I tried restarting the laptop, but it wouldn't turn on again for a while. I've tried restarting and shutting down and sometimes when I press the power button it does turn on, and sometimes it takes an incredibly long time for it to register. The odd thing is that when I click my user and type in my password it works perfectly. Every time i manage to turn it back on, when it loads everything up and my desktop comes up, it always pops up with 'keyboard not connected' on the Bluetooth keyboard search screen. This makes me think that it's not a hardware issue, but a technical one. I'm taking it in on Wednesday to get it looked at, but I'd rather see if I can fix the laptop myself before then.

I have also tried updating my laptop, but I'm not sure if it worked or not.

Help is much appreciated.