can i lose 70lbs in 5 months? ?

Can you? Yes, but not safely or in a way that would be permanent.

Changing your lifestyle (diet and activities) on your way to a healthier weight takes time.

One or two pounds a week is a very high standard to hit.  Some weeks will actually go up or stay the same.

Five months is roughly 20 weeks.  At a reasonable rate you could lose 40 pounds or so.  Probably less if you’re exercising and gaining muscle mass.

Which makes the point that your weight number doesn’t matter as much as how you feel and how clothing fits.  You could lose that 70 pounds and be sickly and weak, or change your lifestyle, lose 20-30 pounds and look and feel awesome.

I would encourage you to simply take it one day at a time, trying to do a little better tomorrow...and before you realize it, you’ll have transformed yourself.

I'd say so. Here's what I did and it worked great. It's simple, but you gotta stick to it. 

Wake up and drink black coffee and water until 2, this will kill your appetite.

Drink 1 gallon of water a day, VERY IMPORTANT this will curb your appetite 

Then for lunch go get a Chipotle burrito its about 1300 calories, load it up if you want so say 1600 cals. Eat the whole thing at once or save half for dinner.

At the end of the day go for a long walk 30 mins aleast. 

After 2 weeks of walking, start lightly jogging and slowly bump up the distance to 3 miles over the course of the next couple months. When you start running add another meal into the mix. I did 3 egg spinach and cheese omelet.

You will drop weight like nothing doing this. 

That's about 3 pounds a week which is perfectly reasonable. 

You need to create an average calorie deficit of about 1600 calories a day. 

Since I don't know much about you I can only guess but probably eating around 1200 calories and exercising for an hour would be around 1600. You can calculate the specifics yourself depending on your BMR and what exercises you do. 

Too much too quick.

Merely eat LESS of what you always eat and the weight will come off gradually and stay off.

Rapid weight loss never lasts and can cause serious health problems

It is not right to make yourself suffer from starvation and working out all day long. No pain no gain is a great motto for those who want to lose weight, but you should not take it literally. You cannot achieve the desired result overnight, and by overworking you are likely to harm yourself.

just try it and see and then you'll know