Finasteride lowers DHT, and even a short 10-day course can briefly upset the hormonal balance in sensitive individuals, which is why arousal and semen volume changed.
The reassuring part is that your erectile function has already recovered within 14 days, which means the effect is settling as expected.
Semen volume and consistency usually normalise over the next few weeks to a couple of months without any treatment; adequate hydration, sleep, regular exercise, and avoiding alcohol and smoking help.
Do not restart finasteride or any hair supplement on your own, and avoid self-prescribed
testosterone boosters.
If it persists beyond eight to ten weeks, a semen analysis and hormone profile are worth doing, so please book a consultation for a proper review.