A) it doesn't matter if people judge you. They'll judge you your entire life and it has absolutely NO bearing on what you choose to do, unless you give them that power. Don't chain yourself to the opinions of others and you'll be so much more happy.
B) 346 pounds isn't too fat for a swimsuit, and neither is 146, or anything above, below, or inbetween. Reframe your thinking - why should your activities and hobbies be dictated by some artificial sentiment attached to your size? When I lived in San Diego I swam all the time and didn't give a flip what I looked like in my suit (as a high schooler, no less!). It was hot, I wanted to enjoy the water. So I did. And I was a heck of a lot heavier AND shorter than you. Might a jerk from my school have called me a whale if he saw? Sure! But just because he says it doesn't make it true, nor should it make me care
C) be careful with time sensitive goals. They set us up for self hatred, in many cases. Will you feel like you failed if you 'only' make it to 150 by then? What will it do to your emotions if your losses are slower? Using goal garments is a great idea, I do it myself (custom corsets at goal weight, purse when I hit 170 awhile back, etc), but linking those with TIME is where the problem can come in. Put another way, would you say I've failed since I've lost and kept off over 90 pounds? Would your opinion of my success change if I told you it's taken five years? I am NOT a failure because my losses have been slow, but if I'd said I should do it in a year or whatever I'd have missed the mark by miles. Why deflate myself (or you) unnecessarily? We can't control how long the weight takes, only the behaviors that precipitate losing it. Basing your goals on a factor you can't control, especially when you're emotionally fragile and have some body image issues, is borrowing trouble.
Just think about what I've said
And buy that swimsuit no matter what your weight. Seriously. It's too hot to not swim.