It really sounds like you’re stuck in that awful “too much vs. not enough” place. Metoprolol can definitely cause low blood pressure, dizziness, fatigue, and worsening balance in some people — especially if they already deal with autoimmune or chronic fatigue issues. But lowering the dose can let the tachycardia and PVCs break through, which is just as uncomfortable.

There are other options besides metoprolol, and it might be worth asking your cardiologist about a few things:

1. Trying a different beta-blocker or class of medication

Some people tolerate nebivolol (Bystolic) or bisoprolol better — both can control rate with fewer fatigue/low-BP effects.

Sometimes a non–beta-blocker option like ivabradine, calcium channel blockers (diltiazem or verapamil), or low-dose propranolol may work better depending on the exact rhythm issue.

2. Checking for hidden contributors to tachycardia/PVCs

Thyroid function

Electrolytes (magnesium, potassium)

Anemia

Sleep apnea

Dehydration
These can all worsen palpitations and can be easy to miss.

3. Asking about a rhythm monitor or EP (electrophysiology) consult
If the PVCs or tachycardia are frequent enough, an EP doctor can sometimes pinpoint the source and offer targeted treatment instead of relying only on medication.

4. Discussing quality-of-life
Your comment that treatment may be doing more harm than good is important. It’s absolutely reasonable to tell your doctor:
“On metoprolol I am too dizzy and fatigued to function. On a lower dose, the tachycardia/PVCs return. What alternatives exist so I’m not choosing between two bad options?”