Did you buy the battery local or have a good factors near you, take the battery off the car, charge it up & take it to them to test, they should have a decent tester that will put a load on it to prove it. If you didn't buy it from them explain what you are doing, most will do it FOC for you
That way at least you know that you know the battery is good, rule of fault finding only change one thing at once & prove each bit as you go along, only work with certainties not guesses.