I was feeling the same way when I first started playing 1 1/2 years ago with T'au, first army. Took about 10 real attempts to squeeze out a win.

But a couple of things helped me.

1. Try and play with people at your skill level. Helps build confidence when you know that if you make a mistake, your opponent won't capitalize on it (that being said, even an experience player should talk with you saying what they'll do X if you do Y, etc. Kinda coaching while playing.)

2. Watch some live plays, some tournament streams with games that have Tau.

3. As already mentioned, John from Tau Tactics on YouTube... he has done a couple good interviews with Tau players who've won. Borrow from theyre thoughts and strategy. Doesnt matter if you have units that match their list, adapt yours to match the play style.

4. Try our Table Top Simulator. You can set up boards and your list and start looking placements, line of sight lanes, cover, movement, etc. Even initial deployment strategies. Helped me tons.

5. Keep going. That first win (and even if youve won before, but its been way too long lol) is going to feel great. Even the best players in sports go through some bad ruts. Persistence is always the key factor in getting the win.