2 things,
1) It sounds like your clutch is slipping, that is why it feels like neutral in the higher gears.
2) It also sounds like your charging system is not working correctly, possibly you may have a really weak battery. Do yo ever have to jump start your car? I have seen Acuras do this, they will almost die when yo give them gas and the battery light will come on because there is no reserve let in the battery and the Alternator can not supply enough power under acceleration at night, because lights are on etc.