I'm smitten with my new "dad", iin?

This may not have occurred to you, given your question, but you can't force anyone to accept you romantically. It doesn't work that way. You're assuming he's clueless when he could in fact know perfectly well what you're doing and simply isn't interested.

One more thing, if you were officially adopted by your 2nd cousin, then incest laws could apply to you if you were to have a sexual relationship with him. However, if he didn't actually adopt you and he's not your so-called "dad" then you can legally have a sexual relationship with him because the consanguinity between you is weak as distant cousins.

I dont think he's clueless. He obviously knows your intentions.Have you considered you might be puting him in an awkward position.As his ward he has a responsibility and duty to take care of you especialy given your recent loss.He takes this role seriously and thats why he doesnt want to bluntly shut you down on account of all the emotional trauma you are going through right now.

How old are you?

If you suck his cock he will like you for sure.

Don't they call a fur coat, a sweater, warm pants with long johns and boots beach wear in Alaska? Don't see how you could expect him to be 'sexually attracted' to you in that outfit, even if you were at the beach.
Try again, if you can find a sauna.

lol you must must be a female ....Don't scare him off

Obviously he cares about you, but maybe he's not interested (romantically) because of the age difference, he's your legal guardian and/or because you're related. The blood relation between second cousins isn't that much and I'm guessing you didn't know him until recently, so I'm not judging you negatively. Just realize that he may not feel the same way...getting your hopes up can lead to getting hurt.

I hope this helps. Before I explain I want to say that yes I think it's normal, however I don't think you should continue to peruse him romantically.

Why I think it's normal:

Before I continue I'm assuming that this new Dad actually spends time with you and does a good job caring for you. I am also assuming that the previous people you lived with probably treated you more like a guest rather then like a member of the family to some degree. Or perhaps maybe you felt that way. Either way, I think what you feeling is similar to the affection people get towards a parent/teacher/older sibling when we are young. I personally remember having feelings towards my mother when I was really young (like pre-kindergarden years)and towards my female teachers. As I grew older however I learned to categorize different types of affection. I learned that feelings I have towards my mom are and should be different then feelings I have towards my significant other. I believe there is some truth to the old saying "every guy wants a girl like his mom" (I want to put some emphasis on "some truth." Although I love my mom more than life itself, I would probably commit suicide if I ended up with a girl like her haha!)

Your situation is complicated by the fact that he is close to your age and you might not be used to having someone so involved or at least someone who has an interest in you (I do realize that is a big assumption).

Why I don't think you should pursue him romantically:

I have two reasons why I don't think seeking a romantic relationship with the guy is a good idea. My first reasons is my personal view that incest is wrong. Although I can see the reasoning behind why people do it, and respect their decisions (as long as both parties are willing) it still seems gross/weird to me and I'm perfectly fine with keeping that view.

My second reason is that I don't think anyone is really that dense. In a previous comment you said you tried to kiss him, you also said you bought a new swim suit for him to notice you, and you also said that you sometimes climb into bed with him to give him a hug. Given your age and assuming that you guys haven't spent a lot of time with each other before you moved in with him, I think he at the very least has a really good idea of exactly how you feel. If I was in his situation, what I would be doing is to try to ignore your advances but at the same time try to not hurt your feelings. What I think he sees is someone who has been through a lot and doesn't want to add heart break and rejection to everything you are dealing with.

-----------------End of my rambling----------------------

I'm sorry this was long, but I didn't like some of the comments that were given (they didn't seem helpful) and I thought I'd give it an honest go. I know I have made some assumptions but I hope I at least got some gears turning.