Sexual health always follows general health, so it's hard to enjoy sexual health with other chronic conditions. Obesity is a known risk factor for heart disease, stroke, sleep apnea and other breathing problems, and osteoarthritis, among other things, and is associated with depression. Unfortunately, not sexy things to think about! And even more unfortunate is the fact that weight gain is common among women experiencing perimenopause; some say that a woman in her 40s and 50s typically gains a pound a year.
I know it's hard to hear, but it's most important to put "first things first," to get regular exercise, achieve and maintain a healthy weight, develop and honor regular sleep habits, and eat healthily both in amount and type of food. Exercise and activity will benefit you most. Yoga might be a good starting point, since it's low impact; it's also been proven to help women sexually, including with pelvic health. If you start there, you can add more aerobic activities as you're able.
Having a health care provider who can help you untangle the issues associated with obesity and menopause can be extremely helpful. If you're not confident in your current resource, you might look for someone certified by the North American Menopause Society. NAMS has a provider locator on their website.
There's no easy single answer for any of us: We're complicated creatures. Start small and keep moving in the right direction—but, most importantly, start!