How can I deal with my partner?

Hi, I'm in a relatively new relationship with this guy I met, I won't say his real name so I'll call him Jake, he has NPD. Me and Jake get along really well, we communicate and we know how to work things out calmly. So far, everything sounds good, right?

Well, what happens is that he needs constant validation from me, compliments about his body most of the time. He is very insecure and jealous, it's not that he doesn't let me have friends but every time I mention someone he gets dry, or if I say I have a best friend he gets jealous and asks me for his social media to "keep an eye on him." (I'm a gay man)

His jealousy bothers me because I find it immature, obviously I'm not a narcissist so I don't know what his thought process is. And no, I don't flirt with my friends, it's all platonic. He also tends to overreact if someone criticizes our relationship, which I personally don't care about. His need for validation does the same, at first it didn't bother me because he's my boyfriend and I love him, I write him poems flattering him which takes up a lot of time, but EVERY DAY he asks me for confirmation that I do love him, more compliments and writings from me, which gets exhausting. And recently he put me "to the test" with a trick question to see if I really loved him. Which I have always confirmed to him MANY AND MANY TIMES

I know it's not my responsibility and I know he can't help it, but I feel like no matter what I do it's never enough. Jake tells me he loves me and he's never been in a relationship where he was more in love, which makes me feel bad for getting upset with him for his behavior.

Can someone give me some explanation about his perspective? Or in general what I should do, I'm a bit afraid that he will get angry with me or misinterpret my words.