I'm 26 and can't lose weight? Please help!?

Hi! I'm a 26 year old female. I'm 5'5'' and weigh 150lbs. Im comfortable when I weight around 135. A year ago, that was what I did weigh and now i'm at 150. I eat healthy (yogurt, chicken, turkey, fruit, veggies, salad, the occassional goodie) and I go to the gym 4 times per week and run for atleast 40 minutes and do weights. It seems as though I'm just getting bigger and it's extremely frustrating. I don't have the money to pay for a personal trainer, but I need to know what I can do to jumpstart weightloss both for myself and my body. Any advice would be appreciated.