Everyone has different size preferences. Personally, I don't find some extra body fat to be a turn-off. I like a wide variety of body types. As long as my partner isn't overly obese or overly thin I don't mind, not because I have anything against people who are overly obese or overly thin, but because those things are often a sign of ill health, and I prefer my partners to be healthy. Keep in mind, though, that health and weight do not equate to the same thing. The number on the scale is not the most important number to go by. There are some very healthy people who would be classified as "overweight." Other numbers are more important. What are your levels like regarding triglycerides, cholesterol, hormones, etc.? How active are you and how often? Those things are more important than the number on the scale.

People have already given you some good advice regarding weight loss, so I'm not going to go into that here, especially because that wasn't your original question. What I will say is this, though: if you want to get healthy (read: healthy, not "thinner"), do it for you. The right person will love you no matter your size. If you try to lose weight, gain muscle mass, etc. for someone else the changes are probably not going to be as lasting as if you do them because YOU want to be healthier. It's a commitment, and the results aren't instant, but if you stick with it and have the right motivation you'll accomplish it in time.

Good luck and feel free to PM me if you need anything else.