(first off, this is a throwaway account as my crush is on here and sorry for my English, not my mother tongue)

Hey, so I have been dating this perfect guy lately, and we're having lots of fun and great moments. Now, I spent my first night with him on friday and the day after (so on saturday) he went to visit a friend of his. Our time together is pretty amazing; he respects my boundaries, he's pretty patient with me, and our night together was perfect too. We were able to tell each other how we feel and I even told him I'm afraid of abandonment (which is a huge step for me). 

So, while he is visiting his friend he didn't write a lot, which I can understand, as he's with her, he's in the middle of the countryside and so he has other stuff to do than being all the time on his phone. Only, today (sunday), I had a panic attack because he didn't write all morning, although he told me he would. Even so, I managed to only write two messages to say hello and to ask if he still wanted to write. That started a mini-conversation on the fact that I needed to be reassured and he replied that he would do that, but not H24 and he would tell me if something's wrong. Obviously, I am not asking for validation 24 hours a day, but I don't want to be the one to make all the efforts either. At the same time I don't want to lose him, because I feel this could lead somewhere... 
Now, I am pretty new to this BPD stuff, so I don't know what I should do from now? Do I explain to him that I need a little more reassurance than just an "hello, how are you doing" when he's away? How can I be okay with him not always reassuring or validating me? How do you deal with that kind of situation?

Thank you very much.