I know it's hard to believe that you're burning 4658 sitting around, but you probably are. The body has to work really hard to sustain itself when it's wrapped in so much excess weight. The only reason your RDI came out to 3658 is because when you're starting out with weight loss, a 1000 calorie deficit is a good place to start. But if you're comfortable with an intake of 1500-2000 & you're losing, I don't see a problem with it.

Listen to your body...if you start feeling tired or hungry often, you're probably not eating enough. Or you might not be eating the right stuff. I noticed that for today you only had 47g of protein, so I'm hoping it's just an incomplete day. You'll probably experience this if you increase your level of exercise too, & that's normal.

It's a process, you'll make adjustments all along the way as your body's needs change, but you'll get better & better at it all the time. Welcome!