okay, i've read the OP now. i think you're an INTP. your posts always sound Ti, at least more than batshit Ne, and P - and yeah, my dad (INTP) can be almost a social butterfly around people he actually wants to talk to. and like i mentioned before, i thought i was an I, but functional preference says E. i think one of the really important things i learned (from people on here, actually) is that extraversion and introversion isn't necessarily about other people.
seriously, i don't buy the stereotypes, or the "recharging" crap. all humans have metabolic energy that is exhausted more quickly when they are interacting than not, and it doesn't have anything to do with being an I. it doesn't make biological sense to say someone "recharges" around people. on the other hand, if you think about it in terms of your dom function, it makes more sense: i "recharge" mentally when i'm using Ne because it's the easiest and most natural for me. this doesn't mean talking to others - it means solving puzzles, exploring, etc. it's not like i don't get tired, but i'm mentally stimulated by it. it makes me want to think more.
so maybe it'd be useful to ask where your best mental stimulation comes from. what gets you worked up and excited about a situation? for me, yeah, i have a driving need to help the world blah blah Fi blah, but what i get really into is being in the middle of the fray and solving a problem. bouncing ideas and tangents and making connections to bring everything together as one. and from that standpoint you can look at whether you're introverted because you tend to pay attention to and get engaged by internal systems/principles most, or extraverted because you tend to pay attention to and get engaged by external patterns/connections most.