You need to be ruthless in your strategy. Work out which is the most lethal of the gold weapons and combine it with gold ice fortresses. Discard everything else. Most tend to favour the towers, as do I. Start out with a gold chest, and then seek to make 4 or more item swap combinations, to both gain extra moves and create more space, even with bronze and silver level items which will give you loads of extra moves. Before you have faced your first dragon attack you should have earned several gold chests along the way, and now be finding the arena is getting a little tight for manoeuvre. Remember I said ruthless at the start of this, well ruthless you must be to keep getting those gold chests - discard the weapons that are not a part of your strategy, even if they're at silver level. By the time you face your first dragon you should have accumulated a dozen gold towers and about 9 or more gold ice fortresses, and still have the space to collect another 2 or more gold chests before you get to the hard levels. By that stage you will likely be spending as much of your moves discarding stuff than creating swaps. Be as efficient as you can. e.g. you can use two moves to create a wooden ballista and discard it v's three moves to discard each bit of wood. I've managed to get to level 99 with this tactic and by the end had about 17 Gold towers and a dozen gold ice fortresses.
You might want to consider a more efficient defence as well. The flat line defence will eventually get breached all at once, leaving higher placed defences facing multiple targets all at once. If you allow gaps in the first line of defence then the higher placed defences can be brought into play quicker and have dealt with a column before the next column gets to them. best of luck Moses. In fact I recognise Nunez as being in my clan. Is that you?