I'm [F/22] not sure how to tell a pastor [M/40s?] that I need some space...

Long story short, my father passed away suddenly this past winter in a work accident. None of us were prepared and so things just got thrown into a jumble when it came to his funeral. Plus, ya know, we were trying to figure out long-term survival without the breadwinner around. As a result, we ended up just letting the memorial service donor (person who kindly paid for it) pick a pastor. We ended up with a really nice man to lead the service and things ended up going well considering we basically last-minuted the whole thing.
At this point, I need to point out that I'm not actually Christian. I'm Buddhist, but I knew my dad was into the whole God thing along with most of my family, so it didn't bother me to have a pastor run the service. I simply bowed my head respectfully during prayers and enjoyed the celebration of my father's life alongside everyone else. However... At the end of the service the pastor said my family and I shouldn't be afraid to talk with him, if we needed it. I told him thank you and smiled kindly at the offer, but in the back of my mind I'm thinking I'd rather discuss my grief with somebody else. Which I did, and got myself in a good place despite all that had happened.
I moved through the next few weeks then just assuming he'd forget about it. He did his part, and I'm glad for the help, but his church is sending me booklets, pamphlets, emails, and all kinds of stuff which I'm not comfortable receiving - mainly due to my own religious beliefs and also because I'm really trying to move past this. The things in the mail only end up resurfacing old memories of my father. I'm not trying to forget him. I loved him so much. It's just how I process things, and I feel like the Christian stuff is trying to tell me how to feel about it, rather indirectly but still.
For these reasons, I'd considered emailing him or calling to tell him to please not send me these things, but I don't want him to think I'm ungrateful or didn't find his service adequate. I really think he's a good man trying to help. I don't have anything against his beliefs either. Mine just happen to be different, and that's okay, but at the same time it creates this barrier between us where no matter what he'll say or do I won't be as responsive as I would with leaders from my own religion. What are you guys' thoughts?
TL;DR - Christian pastor from father's funeral is trying to help me through my grief by sending me pamphlets and stuff, but I'm Buddhist and not really being helped by it. Want him to stop without seeming ungrateful.


Source.