Bella- You've already gotten a lot of good advice here. I just wanted to chime in and reiterate some of it. I was going to suggest that you take a look at
Body for Life for Women but MrsJim already mentioned that. Even if you don't want to incorporate the entire program, it will give you a better understanding of how cardio, weight training and proper nutrition work to build a better body.
My advice would be to ignore the trainer. As was pointed out above, you are not paying her to train
YOU. Those evaluation and gym orientation sessions are different from working with a trainer. If you had been paying for a session with her and she gave you that program, I'd ask to speak to the Director of Training or Personal Services, or whatever they call it at your gym.
If you do that much cardio, you certainly will see results on the scale, but 25-40% of your weightloss may be muscle loss. Not what you want! This will slow your metabolism (not speed it up as suggested somewhere above). You'll end up a thin flabby person.
All my weightloss clients do weight training from the day they decide to walk into they gym. Unless they have orthopedic issues, we do mainly free weights and very few machines. You can do multi-joint and multi-muscle group exercises that are far more effective with them than parking your rear on a seat and doing a machine press. If your goal is isolation of specific muscles (bodybuilding and sculpting) machines do a great job...but if your goals is strength and fat loss, the more work you can do, the better.
My most successful weightloss clients do 4-5 days of cardio of between 30-40 minutes depending on the type and what else they are doing that day, and 2-3 one hour weight sessions a week. And eat correctly
As a trainer, I agree with some of the points made by saengerin, but I think some of her comments are way off the mark. First, no gym can get insurance if they hire uncertified trainers. Yes, there are trainers out there who are uncertified, but they are working on their own. They probably have no business insurance either. Be an informed consumer and ask! There currently are no national standards for certification. Some certification programs are great, some could come out of a cracker jack box. But the actual certification doesn't mean a trainer is good or bad. Experience, empathy, people skills all come into play as well as knowing the correct form for a dumbbell row.
Bella- Don't be cowed by a thin trainer. You know this is wrong for you. Arm yourself with some knowledge. MrsJim gave you a couple of good sources, pop into Ladies who Lift and ask whatever you'd like. If you want to work with a trainer, interview THEM. Yes, it is a business but it's not a very lucrative one.
Most of the people in the profession really do care and want to help people, because we sure aren't doing for the big bucks!
I've never seen fat women bullied in a gym either. Not when I was fat and not now when I'm not. I do understand the "everyone must be staring at me" feeling, but that's not bullying, it's a self-perception issue.
Mel