I don't know where you are from brother but it is especially common in Asian cultures to grow up being very close to your cousins - male and female. This is one of those times when culture is often mistaken for what is actually right and wrong in Islam.
I grew up being very close to my male cousins. And I would confide in them and even meet them and hang out etc. But when I learnt that interaction with my male cousins was in fact the same as me interacting with any non mahram male, it got me thinking... I wouldn't go out to dinners and hang out in a room alone with a non-mahram male. So how can I make excuses in my mind that it is okay to do so with my male cousins? Who are also in fact non-mahrams.
I began to cut back on my interactions with them. It was hard at first especially when parents and aunts and uncles don't agree with what you are doing. But I prayed to Allah and Allah made it easier for me to do so. I once felt the way you do - I couldn't imagine not confiding in them and not talking to them and going to for advise. But Allah replaced them with people who were much better for my Deen and Aakirah. Instead of hanging out with them alone, I would only meet them if others were also present. And instead of hugging them and such, I began creating a distance and now my cousins no longer expect me to shake their hands too. Which is the way it should be. But it's still awkward at times. My siblings hug and greet their cousins and I'm off kind of waving hello. But I do it to please Allah.
Brother, it might seem hard right now because you grew up with these people but ask yourself whether your wrestling and play fighting with them is something that would really make you happy on the Day of Judgment. And just pray to Allah to help you and I guarantee, He will.
I won't lie. I did miss my cousins terribly when I stopped hanging out with them so much. And you don't need to never see them and such but just always try to place Allah first. I would find it an incredible invasion of my privacy and I can physically feel myself recoiling at the thought of one of my male cousins now coming and hugging me. But that wasn't how I used to be. I was always hanging out with them. It took me some time but Allah helped me and He will help you too. Just pray to Allah to show you the way.
May Allah help us all. Ameen.
