That's the same setup that I used for my character ;) In fact, all the way through Tower of Latria, I only used DSS+5, it was the safest way, especially on 3-1 (Those damn squid-guardian enemies have a very potent Soul Ray in NG+)
My suggestion is that you don't start another "Dark" shield, no regular shield, even when upgraded to "Dark"+5 will have the same similar Guard Reduction nor Magical Reduction stats as DSS.
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"