Engine problem

I’ve had this car for a month. Ever since buying it, it’s been nothing but a problem to me. First, Drive With Moderate Acceleration warnings started to come up quite frequently, car goes into limp mode. Then I notice G12 dripping out probably containing oil as well. Now a few days ago, the Engine Oil Pressure Insufficient, Stop Engine warning comes on. The check engine light is always on as it’s converted to LPG and I’m told that it’s normal under the circumstances. Few weeks ago it still had its power when you floor it. Now it won’t even comfortably accelerate more than 2,500 rpm's. And, apart from that, the car is shaky as heck. Where do I start?