how can i become vegan if i we have processed foods at home?!

Time to visit the bulk section! You can get cheap stuff like quinoa, couscous, and beans.
You can make a million things with these things & they are cheap! The beans need to be soaked overnight or cooked for several hours. I make them once a week and eat them in burritos or just as is with onion, garlic & avocado!
Your parents probably won't mind buying you the bulk stuff b/c it's cheaper than buying canned goods. Beans are literally 1/4 the cost when you buy them dried!
I also recommend visiting the website vegweb.com, they have amazing recipes that I use all the time. You probably have a lot of the ingredients at your house already. I am also a student so I understand being busy, but if you make enough for the week you actually will save time!

vegweb.com

Yes, it can be very difficult to be vegan if you are dependent on someone else for your food. I'm a college student, I take classes full time and work enough to pay my rent, bills, gas, and buy my own food. And it's hard, but I do it. If you really want to be vegan, get a job. It's not your parents fault that they don't share the same dietary habits as you.

I don't mean for that to sound mean, it's just the reality. If you try to be vegan on limited supplies purchased by your parents, you will end up losing track of your health requirements. Tofu, veggies, quinua, TVP, rice, etc are not expensive. You'd only have to work one or two shifts a week to buy those things.

Just request a few things on the weekly grocery list: bags of dried beans, peas, and lentils; Veg bouillon cubes; onion, carrots, celery, garlic, and a bag of potatoes. This will give you enough to make a huge pot of soup and a number of baked potatoes for only a couple of bucks.

In college, I used to make a baked potato and top it with a ladle full of bean soup. It's nutritious, it's filling, it's tasty, and it's cheap.

Spam? Really?

fruits, vegetables, grains, and beans are very cheap and what you kind of need to eat if you're vegan. by grains i mean whole wheat bread, brown rice, corn, quinoa, etc. etc. so stock up on those and learn to make dishes based around those things. you can also buy nuts (cashews, almonds, peanuts, and peanut butter) which are pretty cheap as well.

vegan in college... bought food for my mom and i on a limited budget in high school, pretty easy.

hmm....just have an intent in your mind. What you desire will manifest one day if your desire is strong. Intent sows seeds of karma....it will manifest as your reality one day. Just have a positive intent that you want to go vegan and eat a lot of fruits and veggies, and all will happen. For now, just eat less of this processed food, and eat some fruits everyday (like apples and bananas are cheap). Also get almonds and soak them overnight and have like 3 in the morning after peeling skin. Even orange juice is cheap. You can get reasonably cheap vegan food. Good luck!

Campbell's tomato soup is vegan, as are SOME of the Lays flavors. but i agree i dont like eating processed foods either. in the Guides section of my website i have guides on how to live natural vegan lifestyle on a budget :-)
http://wayfaringvegans.weebly.com/

I find processed food more expensive, you should go to the fruit'n' veg stalls. You loads of stuff cheap a big bowl of tomatoes or apples or grapes or 3 cucumbers for ￡1.

Walthamstow market

You get a part time job and buy your own food.
Or you wait until you have the means to buy your own food.