firstly understand that your car only has 4 forward gears, so I cannot quite understand what you are saying that it shifts all 4 gears then gets stuck.
By the description it sounds like your engine has no more torque to give out at 180 km/h in D4 with locked convertor. Mostly in my experience the civic could never achieve more than 180 km/h - which is downright dangerous on any Pakistani highway in a small car. Correct diagnosis is only to first verify these points
engine is in good mechanical tune
ECU is not rigged
no check light or any other bit
good rolling chassis parts.
your last bit of last gear clutch bad is invalid, if that pack was bad your transmission would slip (as if it hit neutral). What you are doing by shifting to D3 is forcing the overdrive (gear 4) to disengage and drop to gear 3. At 180 km/h I believe the engine rpm would be dangerously close to redline in D3.