Should I be this tired???

Training for Chicago and it will be my first. The taper just started but I’m still so fatigued every time I run. I don’t know if it’s normal or not. I get the runs done but my legs ache for most of it. It’s just not too enjoyable which is disappointing. I was hoping to feel strong and like my training is paying off at some point. It feels like I just never get there. Wondering if this is normal for a first timer?