Questions and advice about dental implants

Hello. Has everyone had their health check-up?

I just had a dental check-up, and the dentist recommended an implant. However, I have so many questions and concerns, so I am writing this.

Actually, my molar started hurting last year. At first, it only throbbed occasionally, but gradually it became more painful, and eventually it was painful every time I ate. I kept delaying, but when I finally went to the dentist, they told me it was difficult to save the tooth anymore.
After extracting the tooth, the dentist suggested getting an implant, but my mind is overwhelmed. First of all, the cost is not insignificant. They said it would be over 3 million won... I'm worried about how to come up with that money right now.
Looking up information about implants on the internet has only made me more confused. Some people say it doesn't hurt at all, while others say it was very painful... I'm curious about the surgical process, how severe the pain is, and when I can return to daily activities... I have so many questions.
I'm especially worried about my work life. How long should I rest after the surgery? How many days of leave should I take, and am I able to communicate properly? I also have important projects at work, so I'm 고민ing about how to manage the timing.
And I am also curious about the lifespan of implants. Can they be used for a lifetime, or do they need to be replaced later on... Each dental clinic gives different information, so I don't know what to believe. Some say 15 years, others say lifelong...

I wasn't expecting it at all, but suddenly I have to do it, so I feel overwhelmed.

While delaying the decision, I am only chewing with the opposite molar, and I heard that's not good either. I have a lot of worries about this and that. I would like to hear your experiences or advice.