The fact that you've had no ignition or dashboard lights when you've turned the ignition key is mainly pointing to :
- A discharging battery via a failed alternator (the rectifier can burn out, causing the battery to rapidly discharge).
Start with the easiest thing first. You say that your car started with a boost - a jump start - which suggests that your non-starting problem may be due to the battery or the 'earth'. When you connect another battery to your own via cables, your car is using the other car as an 'earth'.
A quick check - if you have battery jump cables - Connect a jump cable to your battery negative terminal - the earth terminal (black cable) and connect the other end to any suitable metal point on the engine/bodywork of your car, and try and start the engine. If it starts, it's now telling you that the problem is that of a bad earth.
A 'bad earth' can be caused by corroded cables- check both battery cables for a greenish/blue corrosion and/or broken strands in the wire.
Bear in mind that if you disconnect your battery you may lose your radio code. But .. loosen and turn each battery terminal to clean it and fully retighten. Then check the battery earth lead - the black cable - where it attaches to the engine/bodywork. Loosen and clean the cable and attaching bolt. If a car has a 'bad earth' it can cause sluggish/non starting problems.
If you're quite happy that the battery terminals, cables and earthing point on the engine/bodywork are clean, tight and ok ... suspect the battery.
Don't rush off and buy a new battery. Get somebody to jump start your car and then drive to a workshop and ask them to check it out whilst the battery is in situ - they can also check the alternator output at the same time.