I saw a male NHS physio today for my back. Never met him before. He was courteous, polite, helpful. Firm, warm, gentle hands - I felt very safe.
The only unpleasant bit was when he asked me to turn around so that he could see my back, and I got a great big, unexpected, eyeful of myself in a mirror that I hadn't noticed earlier. Ah, the beautiful sagging muffin-top. (I was in jeans and bra.) He never showed any reaction to how I looked. That's not his job. He was completely professional and disinterested.
Though at the end, when we were discussing 'what next', he did mention loosing weight. But it was as part of the overall discussion, and recognised that I wasn't an idiot, I already knew about this, but, professionally, he had to include it. And, again, it was non-judgemental.
So go on, make the appointment. Nobody is going to be nasty about your shape. All they'll want is to help you and to support you helping yourself.