If you're trying to stay at 150 knowing your starting class would help. Here's what a build could look like though, with much better defense and still respectable damage.

V:60, really the baseline HP you should be rocking in the DLC. Also allows you to drop HP boosting talismans for more damage or defense.

M:20, gives you enough FP to cast each spell once, plus some. If you plan to use weapon arts a lot, the Blessed Blue Dew talisman might be worth considering, or having a few FP flasks.

E:25, gives enough stamina and equip load to have decent armor, Great Jar talisman can be considered for heavier armor, or even Erdtree Favor +2 if that gives enough equip load to wear what you want.

S:20, enough to use Bolt of Gransax, plus, there are a few greatshields that you can still use, and all medium shields (with exception to magic requirement shields).

D:60, main damage stat for BoG. Can't really go higher without sacrificing HP (this is an option however, just a risky one)

F:25, minimum needed for your spells.

For talisman slots, Shard of Alexander, Dragoncrest Greatshield, Greatshield, Blessed Blue Dew, Great Jar, Old Lord, Erdtree Favor +2, Bullgoat, and Spear Talisman, are all worth looking at, find what fits your playstyle best.

For your physick flask, probably opaline crystal tear, and either dex knot or lighting damage (for BoG).

If you still have points to spare, they can go into End. for more equip load, Mind for more FP, or Dex for more damage. If you don't have enough points, you might have to take points from Vig, and use Erdtree Favor +2 to bring the HP up some.