Tacks are easy. A few pointers, hopefully some of these will help you to unlock it:
When initiating a turn, move your front hand to the very beginning of the front handle. This reduces wing's angle of attack and makes it more neutral when going against the wind, so it would not act as a break.
Be prepared to let go of the back hand early enough. If you keep power in the wing with your back hand it would slow you down once heading towards the wind.
Some wings do not switch from one tack to another that easily and you have to actively steer them with your back hand. Depends on a wing. Quite a huge difference really.
Lean into the turns, a lot. Make sure your feet position is well balanced, so you can steer the foil with your feet only.
Try to start the turn while you are high on the mast, and loose the height gradually. Keep your weight forward to prevent the foil to stall. Quite many foil setups, when slowing down below some critical speed, have the tendency to point the nose of the board up a bit. You can avoid that by keeping your weight forward, and for example by deliberately keeping the wing way more forward with your front hand than you think is necessary.
If you struggle with toe side tacks, try the heel side ones. For me the toe side tacks were much easier, but some are getting the heel side tacks earlier.
Switch to a slightly faster foil that glides through the turns better, without stopping.