Aviatrix, I don't know what kind of physical shape you're in, but assuming you don't usually get tired, say, driving, you shouldn't worry that a flight lesson like the one you describe leaves you feeling drained. Perfectly normal. Thinking hard while learning new hand/foot stuff... it taxes the whole body. Adrenaline leaves you feeling tired, too, sometimes.
Don't be discouraged if you feel a little overwhelmed, but don't kill yourself trying to keep the pace set by the instructor. The comments above about quality vs quantity are spot-on; if you need a moment, take a moment. If you want to try slow flight in ground effect vs doing as many t&gs as possible in x minutes, ask the CFI to let you try that.
There's a point where a student just isn't going to benefit from the training, when they feel exhausted and stressed out. It's gotta feel like fun, even when it's challenging.
Speaking of fun, I'm glad you are OK with the 152... I started in a 150, and grew very fond of it. Be leery of anyone trying to talk you into something faster during your training...I made that mistake, convinced by the instructor that it would save me time and money somehow, but looking back, he probably just wanted to be more comfortable, and bring in more money for the school. Obviously, if you have access to a 172 or something, you should get familiar with it if you want to take more than 1 passenger on longer trips, but for now, I'd say a 152 will be just fine. It's not like you can't learn what you need to learn in a 172 (it's also a good trainer), it's just that a 152 will need a little more work and concentration to fly gracefully, and that's a good thing. The fact that you'll pay less for this is icing on the cake.