The key to baking is measuring.
There is absolutely no way for any of us to help you if you are not measuring your ingredients. The difference between half a teaspoon truly can make a large difference.
In fact, if you had been measuring your ingredients during your 30 tries, I highly doubt you'd be asking the question at all, much less "beating your brains out" trying to figure it out. You can't figure something out if you don't keep records of exactly what you've done.
Exactly what type of flour are you using? unbleached? self-rising? whole grain? all-purpose? other?
Exactly what type of yeast are you using? cake? rapid rise? bread machine? other?
Are you adding salt? or sugar?
Try measuring, it won't add more than a minute or two of time and will also provide a scientific method by which you and we can determine what is going on. Measure the quantity/weight of ingredients. Measure the temperature of the water you proof the yeast in. If you are not proofing, then you need to explain exactly the recipe you are using and what order of steps you are using. Measure the air temperature in the room you are allowing the dough to raise. If you can, measure the humidity as well.
Speed in raising dough may be fun to witness, but experienced bakers know that this is not the secret to quality product. The ideal rise, depending on the type of bread is minimal yeast and a long rise in a cooler temp. The longer the dough is allowed to rise, the more flavor is developed.