Would love to make it to a size 7

I just joined a few days ago and have been keeping up with my daily counts.
The thing is, I've been working out at a gym since June, and I have not seen any significant results. I've been pretty active my whole life (ex-gymnast, black belt (though not actively practicing), modern/jazz dancer), but things have slowed down in several ways since I got married 7 years ago. I've been at a certain size (around 9-10) for all of my adult life (although I wear 11-12s since I like loose fitting clothes), have been pretty muscular except for the recent flab due to being out of shape somewhat). I would LOVE to be a size 7, and 25 lbs lighter (I'm at 150 right now--never, never have been this weighty). I honestly don't think it will ever happen. I know pounds are not as much of an issue as inches, but I've never been a small person, so I'm not trying to over-reach and yearn for a size 3 because I know it won't happen.
So now, working out at the gym, I'm seeing some tone come back, but no weight has come off nor can I fit into a pair of size 10 pants that I want to get into. I've been listening to the experts who say that weight training should be the focus and cardio secondary. It makes sense--just the presence of muscles burn fat and calories. But I think that I am bulking up, despite what trainers say (women don't have enough testosterone to bulk up), but the fact is, it seems I'm getting nowhere. I'm a pseudo-vegetarian, and I wasn't eating too healthy for maybe the first couple of months that I started up at the gym (thought I could eat fried fish and fries and be okay). Now I'm back on track, thanks to myfitnesspal.com. But I wanted to see if anyone had any advice for someone who's not too heavy (I'm borderline) but a bit bulky from having strong muscles. I don't want to go over my THR because I'll burn my muscle, but I don't know how else to get slim. I've done pilates and yoga, but I want to burn more calories. Should I not use too much weight and focus on mid-level cardio?

Trying to see what REALLY has worked for people.

Thanks for the tip. I had thought about doing that, and tried it for a week until I met with a trainer (although I'm not seeing one regularly--can't afford it!), and she told me her tips--3 days weight training a week along with cardio after the weights, with alternate days doing cardio. When I was doing cardio for that week, I was really going hard-probably going over my target heart rate, which later I remembered burns muscle, which is not what I should do.
I'm thinking of doing that 10 minute trainer system and save the money from having to pay the monthly gym membership. To think of doing cardio for a whole hour makes me cringe. I get so bored and I need variety. It takes a lot in me just to do a solid half-hour on a machine. I don't know. I might try 3 months of focusing more on cardio and see what happens. If I see the weight drop, I might continue.
Thanks again!

Anyone else have any thoughts?