Im having girlfriend issues and i need help please?

My girlfriend loves money. And in my mind im always wishing i could get a job to really hand over the checks to her because i dont spend any bit of what i get on me. And i really dont care about money. Everytime i get money i save it, i started to not tell her when i would have money because she calls me out infront of people whenever they want stuff like 'pizza' sent to their house and crap like that and i say im broke (i usually get up to like 30 bucks every week). Also her mom hands her money like its nothing but latley shes stopped and its gotten worse. She tells me i use people because i have money saved up, and when someone asks to buy me food i say sure instead of saying i can pay for myself. I dont lie to them and i dont see how its bad when they want to buy me food yknow. Anyways shes crazy about money and when she gets some from her mom right away she tells me that she will not spend it on me. I say babi i dont even want your money, it still hurts though cause her i am thinking about spending everything on her. I take her all accross town all the time waisting gas on stupid crap places only to make her happy. But she says i use her and her mom because her mom is the main one who offers me food. I clean her moms backyard and do other things here and there (dishes) and crap in her house. So i just see it as equal exchange. Ok so whats my issue is, the other day i was highly under E in my car but i still took her to her friends house. Had a cool time until it was time to go she was with her friend and they were talking in my car. I only have a 20 on my name at this point and she knew about it but i was saving it for food and ov course gas but for me to visit my friend. So my car was on and they were in there for 20 minutes and i came by and said are we going? or just turn the car off. She yelled saying im talking bye! and i responded with im way under E and i have no money to keep the car on like this. She responded bk shut the **** up you have a 20 quit lying and quit using ppl. I just walked away. Also she sorta puts me down infront of people.. like things like 'quit trying to look cool just cause your pal is here'. or when im really happy i get hyper and just joke a lot making ppl laugh and she bluntly calls me annoying and it puts me down so i chill out. I told her when im hyper im really happy but she says i get too annoyinh, so i always watch out on how smiley i get... crap like that which i do talk to her about it but she continues. Iv been with her almost a year now and i really realy love her crap tons. Iv put up with a lot and im fine with people calling me crazy for even sticking round. Her friends even tell me they dont know how i do it. Being with her and not knocking her out. -sigh- plz help