Commandos are not squishy marshmallows (the Caldari one might actually be a marshmallow, but it is by no means squishy). You should probably fit your dropsuits better, as well as upgrade your core skills.

The basic building blocks of your suit. Things such as shield, armor, stamina and PG/CPU upgrades

Core Upgrades are refereed to as skills that improve your stats without the need to use a modules. These things can do anything from increasing your Dropsuit's CPU or PG, to decreasing the amount of time it takes to hack and even increase your Base HP.

The skills that passively increase your base HP are:

• Dropsuit Shield Upgrades (+5% Maximum Shields per Level)
• Dropsuit Armor Upgrades (+5% Maximum Armor per Level)

These two core skills are very important, but are best saved for when you've obtained the other neccesssary skills first. As for which one of these two you should go for first, it depends on which which dropsuit and/or 'tank' style you are using.

If your running a Caldari or Minmatar suit, and primarily run Shield Extenders, Dropsuit Shield Upgrades will give you more bang for your buck, while Dropsuit Armor Upgrades should be the thing you upgrade if you run Armor Plating or running Amarr or Gallente suits.

Nah, I'm just a scrub with spreadsheets.