Should I try to wear a bikini or no?

I have dermatilomaina which means I pick at my skin plus a stomach condition (I haven’t been diagnosed yet) that causes me to not be able to gain weight so I look sickly. My dermatilomaina makes it look like I have bad body acne but I don’t I had my dermatologist look at it. The reason I’m asking about a bikini is because there’s this BBQ that I’m going to possibly with my friend and the person hosting it has a pool. I really want to swim but I hate my body so much. I normally wear a sweatshirt and long pants even in 80 degree weather, that’s how bad it is. I’m scared people will think I’m disgusting but I really want to just have fun, help. 😭

Ignore my hair I just got out of the shower.

Here’s a picture of just my arm so you can kinda see what my skin looks like.