Straight up. I'm so ugly that when I'd go out with my parents, they'd honestly pretend I wasn't their kid. My dad used to have a secretary he'd introduce as his daughter, leaving me behind hidden in the stockroom while he'd take her to lunch. ("It's just business", he'd tell me.)
One thing that really helped was when I made the decision that I was worth fighting for. That I wasn't going to let my attractiveness fucking define me. I am worth more than that.
You are, too.
First thing is first: get yourself into some therapy. You need it. Bad. Right now, the vibes you're giving off will leave you incredibly vulnerable to abusive relationships. You need to fix that shit up. You need to work on your self-esteem and confidence. Therapy is going to help with that.
Secondly, consider checking out the skincareaddiction and makeupaddiction subreddits if you haven't already. One thing I noticed was that when I started taking better care of my skin learned how to apply makeup, it made me feel like a 'normal' girl. It amazed me just how much of a difference good skin and makeup could make.
Third, stop worrying about being naked. If you've got a lot of loose skin, maybe it'd be worthwhile to save for a tummy-tuck. One thing I do is wear a corset: not so much to get some sort of extreme hourglass shape, but because it makes me feel sexy and really improves the lines of my clothing.
For what it's worth, I think you're so focused on your disappointment about loose skin that you're thinking you're ugly when you're not. But, seriously, the loose skin can be fixed.
As for finding potential partners, stop going out there looking for partners and start doing things that will increase the number of people you meet. For me, I'm the member of several clubs. I met my boyfriend (a rather good-looking doctor, so don't believe that crap about people being 'out of your league'. That's bullshit.) during a game. I'm not a witty woman, but he liked my confidence and cheerfulness, so he sought me out because he enjoyed my company.
Given your self-esteem, you'll have more luck finding an activity or a community online to join. Consider joining an MMO: as insane as it sounds, I actually learned how to small-talk and flirt while roleplaying on WoW. Both are incredibly fantastic skills to possess.
Look, I know it's really hard to go through life feeling ugly. But you're 26. Your world is just beginning. Seize it.