You got outnumbered and failed to outplay the enemy. That makes 100% perfect sense.
More expensive ships are not an I-win button. In fact CCP has spent a good chunk of the last 5 years worth of ship balance changes moving away from this exact paradigm.
Also Gallente racial flavor is rep amount boosts, and if you run the math they’re actually quite strong, especially solo. If you’d had a resist bonus you actually would have died faster. If for whatever reason you were buffer fit then I would recommend flying something other than Gallente. If you really want to fly Gallente for some reason then you should adjust your playstyle and fitting to take advantage of the strengths of the ship. If you try to use a hammer to cut things of course it’s not going to work well, use the tools you’re given in a way that makes sense for those tools and you’ll do much better.
EDIT: I see someone dug up your killmail. That tank is lousy. I’m going to make one modification to @Wanda_Fayne’s fitting modification (which is fantastic btw) and say you shouldn’t even have a DCUII in there. Assuming your Armor Comp skills are above 3 you’ll get more out of 2 ENAM 2s than you will an ENAM 2 and a DCUII.
Also looking at the value of your loss vs the last loss for each of those pilots for the ship they were flying they total 81m while your loss is valued at 89m, so they had almost as much ISK on grid as you did but three pilots. Of course they’re going to win unless you fly far better than them!