Why should I continue my SIP when it is showing loss on SIP investment so far I made

1.1) SIP invested on 12 December 2007 Rs. 5000.00
1.2) 16.59  Units are alloted on SIP investment made on 12 December 2007, i.e.₹ 5,000.00 devided by  ₹ 301.24 being NAV as on the date of investment.
1.3) Valuation as on 22 March 2009 of my such  investment made on 12 December 2007 will be detarmined as, 16.59 units multiplied by NAV as on 22 March 2009 , as follows:
16.59 unites X Rs. 117.16 (NAV as on 22 March 2009: ) = Rs.  1,943.68
1.4) Such Valuation of my investment as on 10 May  2020 of those 16.59  units will be determined as multiplied by Rs.  585.45 ( NAV as on 10 May 2020) = Rs. 9,712.61
1.5) So my return on investment will be 4,712.61 i.e.  ( ₹ 9,712.61-₹ 5,000)

1.6) If I consider the return as on 22 February 2020, at the NAV of ₹ 791.92 such valuation will be:
      i) 16.59 units X ₹ 791.92 = ₹ 13,137.92
      ii) the return will be ₹ 8,137.92 i.e. ( ₹ 13,137.92 - ₹ 5,000.00)