At one week of age, I would be looking for feeding every 2 hours during the day...more often if he shows any hunger cues (you won't over do it). You may feel like you are wearing him, but that is perfectly normal!!
The benefit of frequent feeds will be that you will establish a good supply, that you both will become more comfortable with what you are doing, and you will gain confidence.
Generally it can be helpful when starting out to offer both sides to obtain the frequent stimulation....but let him finish on the first, you don't need a set time limit. When he is done..or you notice that you are be used more as a dummy than a source of food, offer the second. He may only be on a short while, but then you just start with that side the next feed.
If you are eating fine, don't worry about having to take in more...you don't need to go over the top with food and drink...just be sure you are taking in an adequate amount...don't skip your meals, have some healthy snacks, etc.... The key to supply is frequency of feeds and "emptying" the breast...although you will never actually be empty.
Find a relaxing location to feed and try different positions to see what you are most comfortable with. You will likely start to see an increase in weight next time.