Help being a better frost mage

[beefdidy]

hey yall, im ilvl 640 running frost, IN/MI/PC trying to get into raiding for the first time ever really.

here's my armory:
us.battle.net/wow/en/character/sargeras/Gangstamage/simple

i think i'm doing fine, but i know i could be doing better since im simming at ~23k and im pulling 17-19k on bosses like butcher and kargath. im also using ask mr robot to tell me if a specific piece is better than the other, i got a few ilvl upgrade pieces but i'm not using them cause AMR said my current pieces are better, due to better secondary stats and sockets and whatnot.

here are my logs, im gangstamage:
warcraftlogs.com/reports/QW7GzdjNRPZ8gbwq/#fight=152&type=summary

i know im not potting and i should be, but i always forget to buy them. they're like 45g a pop on my server and i'm poor roughly how much of a dps increase do i get out of potting?

with regards to my opener i try to:
precast fb
IV+MI
FO
PC
ice lance if FoF up
dump ice novas on crystal when no FoF
dump any BF on crystal if no FoF/IN
water jet+2xFB when crystal dies

i also save my FO for PC, since i read that this is a dps increase, correct? and i try to use IV and MI whenever they come off cooldown

also, i think that the dps readings on my recount and on warcraftlogs slightly differ sometimes. i sware my recount said i pulled 20k on that heroic kargath kill i linked, but warcraftlogs had me at just under 18k. i experienced something similar with a number of fights, thought i was doing more but warcraftlogs says otherwise. is this just me? am i doing something wrong here?

thanks for the help in advance yall