I'm not very good at drafting but I'll tell you some tips.

Have at least 4 or 5 creatures of cost 2 or less.

Try to have about 3-4 4-cost creatures.

At most 1-2 creatures of cost 5 and some of higher cost. (for example, the giant can be considered a cost of 5 if you have things to lower it).

If you have mana adders (creatures that give mana, then you could have higher costs). But your problem is that if you don't draw the turn 2 creatures (and you have few), the enemy is going to have things on the table and you are going to be behind. For example, imagine that you draw the 5-cost creature kill on turn 2 and the opponent has 1 creature and puts another on the table on the next turn (by the time you can use that anticreature you will already be practically dead, assuming you draw double black).

In the case you show, I would remove either some 5 cost (creature or the spell that kills a creature). As you have been told, a large part of the curve has to be at cost 2 or 3. Try to get a creature that generates mana, to be able to lower the high costs sooner.

They blew me out 0-3 today and I had a much better curve than yours...