General aviation pilot reported disorientation and a loss of controlled flight while climbing on a missed approach in instrument conditions; resulting in an altitude and heading deviation. The pilot returned to the ATC clearance and continued the flight.

Narrative

While returning to NC from spending the holidays with family in OH; I found myself in IMC and on an IFR flight plan with predominant ceilings in the area at 700 ft. AGL. As I was also approaching my six month currency for 6 approaches in the past 6 calendar months; I decided to complete several additional approaches because of the ideal weather. I put together a hasty plan of HBI RNAV 21 missed; SOP ILS 5 missed; then SOP RNAV 23 full stop. I briefed myself on the approaches with the autopilot set well in advance; then made the request to Greensboro Approach. I completed the HBI RNAV 21 to standard; but while on the missed for training; I began flying the missed for the next approach because I had already brought it up on my Ipad. Whereas I was supposed to continue runway heading to 3;000 ft. MSL; I began a left turn at around 2;200-2;500 ft. I realized the mistake and corrected; but my overly-aggressive right turn back on course (53 degrees) resulted in my pitch autopilot servo disconnecting and an inadvertent altitude loss of ~250 ft. in a matter of 3-5 seconds. I was able to use IMC fundamentals to correct the unusual attitude; but I had deviated from the prescribed 210 heading by ~80 degrees left then immediately into 90 right to correct all below the prescribed 3;000 ft. MSL. The almost 60 degree L/R roll excursions; as well as +/-30 degree pitch excursions and altitude deviations up to 250 ft. nearly led to putting myself into spatial disorientation.When I analyze the causes of this event I see overconfidence in thinking that I could put together a hasty IFR plan in IMC then execute it solo with a lack of recency (last IMC approach in this aircraft was Day 0). I frequently fly IMC in a very stabilized helicopter; which I believe contributed to this overconfidence. I omitted the fact that the aircraft is a two-crewmember aircraft with stabilization equipment; not a light and very responsive aerobatic aircraft being flown single-pilot.Additional human factors: I had gotten up very early to take my girlfriend to the airport for a separate flight; but had then napped upon return to the house. I was also a bit preoccupied with ensuring she knew of the change of plans to do additional approaches so she wasn't concerned about my later return.This was a humbling event that will certainly inform my future decision-making regarding similar situations.