Will not start

Bought rig used in February of this year. Changed water pump, serpentine belt, new tires, brakes, tie rod ends, axles, filters, spark plugs, and just changed the oil topped off with coolant and about a half a tank of gas. Also had to replace stereo because it quick working. I noticed coming home around 9:30 last night my dash lights shut off and then about five minutes later still driving just tired back on. For about four days I have noticed the dash lights kind of flicker but assumed just a fuse or loose wire or bulb nothing to worry about. Two days ago my fan just stopped blowing air (the air conditioner has never been used needs recharged since purchase.) And starting making a terrible noise like the motor was going to go out. Then stopped and worked fine until half way through the day, yesterday did it again. Shut it off and turned it back on worked fine. But then as we put it in drove and began to pull away we hear a loud hissing noise like a big vacuum blowing air or tire losing air but way louder and more air shifted in park real quick got out shut it off them turned it back on and it was gone and it did not make sound anymore. Now today after parking it last night same as I always do it refuses to start up cranks over and wants to start but wont heckled oil coolant security wiring setup at ignition in the steering wheel column, battery has power it is getting fuel. The fuses all fine wiring all fine, everything works great just wont start. Please please help I have two little kids I am a nurse and my life already bad enough without a vehicle that is always breaking down sucking every nickel and dime I work for that I already do not really have to spend.