2002 Honda Civic Engine tick HP drop

Ok so in july I got a 2002 Honda Civic Ex. When I first got it it was great and ran perfect. I put in a true cold air intake not short ram and got halo headlights. Once I put in the cold air intake I could tell I gained about 10-15 hp and nothing was wrong with the car. Then I went to a place to change my oil because I didnt feel like changing it but one week later my engine started ticking. So I checked the oil and it was completely burnt! Like they didnt even change my oil! It sounds like a lifter tick but my hp is extremly dropped and when im on the high way I get 30.11mpg! I got 41.32 mpg before the tick. So my question is would a lifer tick really hurt my gas millage and hp that much? Also there is a squeeking noise when I hit the gas a sertin amount, that was not there before the tick was present so its not the intake making noise. Idk what is wrong with it, I just want my hp and good gas millage back. Please help