I have a 2012 Honda Civic and having problems with engine misfire. About 4 months ago I was on the freeway going up a hill that is not very steep at all. My car started to loose power and then started getting a little shaky so I pulled over at the next exit. My family mechanic met me and plugged in his code reader and saw cylinder 3 was misfiring. We swapped the spark plugs around and the ignition coils but still cylinder 3 was misfiring. I think he said it had low compression and the cylinder head was burnt so then he took it to get the headgasket resurfaced. I think the timing chain also got replaced along with all new sparkplugs. Once the work was done the car ran normal again. Car has been running fine for about 4 months. but then the same thing happened again today when I was going up the same hill on the freeway. The shaking wasnt as bad as the first time but I can tell that the engine was misfiring. Anyone know what can be the cause of this or any suggestions?

Also some things to note: about 160k miles on the car. Constantly drinks oil. Im pretty sure there is not a leak because there is no oil on the floor where I park my car. Also my car already has a hard time changing gears and is hard to gain speed when goin up a hill. It feels like my car gets stuck in a certain gear when going around 40-50mph and will not change gears unless I let off the gas for about 1-2 seconds, then my car shift and then I can go back on the gas.