Installed new breaker to relieve load in existing circuit. Still trips new breaker
You need to know what's all on these circuits and what they pull.  There's no substitute for this. 

So it comes down to looking at the manual for every appliance on the circuit.  Considering of course that the appliance shouldn’t draw if it's off.  

You can also use a Kill-a-Watt to directly measure; pay closer attention to VA than watts.  

Once you've done your tally, you will surely discover an obvious problem, like 23A of loads on a 15A circuit. Rearrange as necessary.