Need some guidance on inside pitches

Any advice or input will help. I have a monitor and wired controller. I just cant seem to hit it especially sinkers and fastballs but really anything inside honestly. I go into practice mode on like legend sometimes hof with fastball speed sliders turned up all the way and only fastballs in to get the timing down and I play on hof usually but all star today because I was just not hitting. But I get it down and I go into a game and I’m just fed low and in sliders or low and away sliders and since I’m just looking for a fastball I have to swing very early and basically no time to even see the pitch hence missing the pitch at my ankles. And then they’ll throw me the pitch I’m looking for and I still miss it I just don’t know what to do can anyone please give me a tip or trick to get this timing down.