Or there is another option. You could look into cutting a few of those dragons and putting in some Pokemon that give energy every turn. For example, the last versus reward ladder had two Palkia EX that could help fulfill your water needs. Or, this versus ladder's reward ladder has the (much better) Metagross GX who can fulfill your metal needs.
The difference between the two is that Palkia EX requires you put two water energy on it to use an attack for 40 damage and pull water energy from your deck onto your benched Pokemon. The Metagross GX has an ability that allows you to place one metal or psychic energy (once per turn) onto your active Pokemon from your discard pile. The kicker? Your turn doesn't end and you can still attack. While that doesn't sound like much, picture having two or three of those bad boys on your bench. You can constantly refuel your active Pokemon without having to worry about discarding energy if the attack calls for it. There are many other Pokemon that give energy as well. In the latest expansion, Malamar has an ability that allows you put psychic energy from your discard pile onto your active Pokemon.
The point I am rying to make is that if you give yourself the ability to attach multiple energy per turn, you speed your deck up. By doing so, you'll be able to throw volleys at your opponent while they are still trying to catch their breath.
Another great way to get energy is Max Elixir. This card can be very useful if you run a significant amount of basic energy (at least twelve), and allows you to place a basic energy of your choice from the top six cards of your deck onto one of your benched Pokemon. If you have an easy way to switch out your starter, you might be able to land a powerful attack on the first turn.
Try to build your deck around Pokemon that need no more than two or so different color energy to attack. You don't want to have to sit and wait until kingdom come for the appropriate energy to come along. Your opponent won't be waiting around for too long if they can help it!
If you must run a slow deck until you find a way to speed it up with an energy giving attack or ability, you should at least find ways to stall your opponent's quick decks. Trainers like Team Flare Grunt, Team Skull Grunt, Mars, Crushing Hammer, and Enhanced Hammer can slow your opponent's deck down and allow you to catch a small breather. Attacks like crunch also help in that area. If your opponent doesn't have energy, they can't attack. Don't be afraid to toss in a few Max Potions to help heal your wall, especially if you are going to go the stall route.
Truth be told, most players usually roll fast decks or stall decks if they can help it. Players that have decks that are neither find themselves stuck between the moon and New York City (a Christopher Cross reference!) and usually end up easy pickings for those types of players.
I hope this helps!