Starter vs battery

If it starts with a jump the starter if fine. The colder it gets, the less cranking amps your battery can produce, all cable connections must be clean and tight. And a 2 year old battery should be good unless it's a $40 cheapo, in that case it might have lost it's CCA's.. or is not big enough in the first place for your car. .a portable , if you mean like a charger, does not put out enough to matter when starting.

Well this second time around I had no success with jumping so I'm assuming it's the starter.

battery can draw juiice without holding charge battery is shorted out change battery

I went through the same thing for 2 years. Here is what I finally figured out. Let me also ask you if the power locks and powers windows are working on the drivers side door? Common problem...the wires that are in a sleeve within the drivers door begin to short out. When its in the process of shorting out, they will keep some sort of light or other small feature (I forget what) on because of the short which in turn drains the battery. Here is the fix: open up the drivers door and look for the sleeve of wires. You may need to open this sleeve up and you may need to cut it very carefully to access the wires inside. One of the wires inside is either cut/or broken or is about ready to break and is shorting out. Thus-causing that small feature to stay on when the car is off and thus, drains your battery. If you are not having issues with your power window/doors, the short may not be as far along but check the sleeve of wires in the drivers door and I think you want to focus on the white one or ground one.