I posted above but have another thought. You seem a little depressed - understandable if you are not happy with where you are. I'm going to suggest that you "fake yourself out" by being proud and happy even if you are faking it.
Stand up as tall as you can - pull your waist out of your hips, pull your chest out of your waist. Rotate your shoulders back and pull your head out of your shoulders and neck. Pretend your head is being pulled upward by strings attached to your ears. Walk with authority and a pep to your step. It will seem hard and will tire you out quickly but keep doing it and those muscles will get stronger and it will become natural. You will look and feel taller/slimmer.
Best wishes!