I think I can be hard on myself in terms of my appearance. Generally, though, I perceive it as more helpful and healthy than not. It's motivating and I'm used to holding myself to higher standards for many areas of my life. It's certainly not without its negative effects as well, but overall it works for me. It doesn't help that I'm a bit ignorant to what makes males attractive. It's just not something I get, so it makes me a bit more insecure when interacting with others for the first time. I usually don't care what others think about me from a self-focused perspective, but in the context of, say a session, I want them to get out of it what they want. If attractiveness is important (and there's nothing wrong with that to me), I don't want to disappoint them. It's hard for me to trust others at their word when it comes to politeness because many people often prioritize being nice over being honest. Not to say that's always bad either or anything, but it doesn't do much to settle my feelings on it.
So as far as my laugh, it follows that same pattern. I don't find mine interesting or attractive, with no innate way of knowing what an attractive male laugh is. I fight the laughter, in part because of all that I've said so far, but also because being vulnerable does not come naturally to me at all. I like to be prepared for everything and have no surprises by default. I enjoy being tickled because it disrupts all of that needed control, but I still reflexively fight it. Depending upon the circumstances though, that breaks down fairly quickly when being tickled.
I'm not a shy person, except when it comes to tickling. So in general, that also makes it a bit harder to get my mind in the right place. But all this said, while I find it does make it harder to be on the lee side of the feather, with the right people, I still do it and still enjoy myself a great deal.