You could spend 2-4 weeks at a slight surplus to try and boost your metabolism then drop calories again or stay in a slight surplus for a longer period to try and lean bulk, all depends on your goals really
That would depend on what you like to eat and where in the world you live - eating 3 times per day you would need approximately 40-50g protein per meal
Breakfast could be 6 eggs (~40g protein) or porridge / oats made with full fat milk and some Greek yoghurt
Lunch aim for 200g of a meat...
You can but best nutrition is through food, you weigh ~135 lbs so you should at most need 2500 calories (probably less) a day to grow , target eating 135g a day of protein, eat a minimum of 70g a day of fats and the rest from carbs it should not be too hard to do
Eat surplus calories (250-500 calories above maintenance), train hard 3 x per week minimum (compound exercises such as bench press, overhead press, rowing exercises, chins, squat variations and deadlifts) and sleep, that's it
You shouldn't rely on daily weight fluctuations for success in weight loss, I weigh in daily and log the average over a week then I look at the general trend (on a week by week basis) over a period of at least 4 weeks before deciding if I need to alter anything unless of course the scale is not...