This is the only man that fits all the clues
1884 Nov 23. Born Essex
1891 census at Faraday Rd, Leyton
1902 Married Sarah Elizabeth Smith in West Ham
1911 census at 38 Buckland Road, Leyton E, Essex
1915 Jul 25 Landed in France
1918 Mar 28 DCM gazetted
1919 Feb 2. Discharged (xix) means :- For the benefit of the public service after 18 years service (with a view to pension under the Pay Warrant)
1919 Feb 3 Commissioned 2nd Lt, Essex Regt
1921 Jan 26 Joined ADRIC with service no 1606.
1921 Feb 4. Posted to H Coy then M
1921 Sep 1. The undermentioned relinquish, their commissions on completion. of service. 2nd Lt and retains rank of 2nd Lt, Essex Reg, H Hammond DCM
1922 Jan 19. Discharged on demobilisation of ADRIC
1933 Nov 21.The undermentioned having attained the age limit of liability to recall, cease to belong to the Res. of Offs.: Essex R.—2nd Lt. H. Hammond, D.C.M.
1939 Register. Living with wife Sarah at 82 Hall Lane , Chingford M.B., Essex. He is a Supervisor Electrical Wire Works