There could be a few things going on.
First, what is your guild situation? Are you in a guild with a good number of active players that are contributing gold and completing a number of guild tasks every week? This is the best source of glory and gem keys to help you build up your deck. Of course, being in an active guild also means contributing gold to those tasks (which gets us back to your original question), but you should find the return more than worthwhile.
Second, you may find it worthwhile to grind your way to PVP Tier 1 early in the week, then consider switching to Casual PVP. In Casual, you can refresh your opponent choices for just 50 gold (rather than using Gems like you would need to in ranked PVP). While you are spending some gold, you can pick and choose opponents much more easily this way and should be able to avoid some of the more difficult and frustrating defense teams.
Third, there are some play-styles that are more effective than others. One popular way to take on very powerful teams is to use a deck that “loops”, meaning that once you are able to fill one key troop with mana, you can control the board in such a way that the opponent will usually not get another turn. A combination like Hellcat, Alchemist, Goblin Rocket, Goblin Rocket doesn’t need any traits and can beat any team that doesn’t have Queen Mab or other troops that can easily freeze you. If you’d like more information about how looping works, just let me know and I can expand or refer you to an explanation elsewhere.
Fourth, and maybe this should have been first - what are you spending your gold on and why do you feel that you need more than you’re making? Your focus with the gold that you generate should mainly be on levelling up your kingdoms, then contributing a reasonable amount to your guild. Once you get your kingdoms up to reasonable levels, you’ll start to generate a significant amount of gold just from collecting tribute as often as you can.