Not sure if i should do this or not?...?

My ex broke up with me about 8 months ago. While we have been able to maintain a good friendship and a bit of a fwb relationship as well, things do at times still get rough and we do still fight. We haven't really spent much time apart since the breakup( we even hung out the entire day he broke up with me) I didn't have an problem with this in the begining, and while i do not have any romantic feelings towards him anymore and it's been clear we are not getting back together i still am questioning weather or not to continue the friendship. I know we are both going to start seeing other people soon and i really don't want to end up hurt but i have a feeling i will. I don't know what to do. I told him that we did need to talk soon, but i don't know how to tell him how i feel without him taking it the wrong way and getting upset( he tends to get like that) I know i want the fwb to end for sure, but i feel that if i tell him that the friendship will be over as well. it's becoming too much for me and i don't know what to do. All the time we have spent together cannot be healthy and i feel that i need the space from him to fully heal from the breakup and i cant get that if he is always texting and inviting me over and just being there. I'm sure he doesn't feel this is a big deal, but it is to me. So how do i talk to him about these things without hurting him or ruining the friendship. Or should i even do it at all or just leave it alone? Any advice would be helpful and appreciated.