My fiance/sons father told me today that he needs alone time. He has been extremely distant lately and he told me this after days of asking him what was going on. When I asked him if he loved me he said " of course" when I asked next if was "in love" with me he said "maybe not" he doesn't know. I need some advice cause I'm so confused..

The needs space, or needs time, is basically saying it is over and he wants to break up, but leave you hanging just in case things don't work out and he needs sex or something.
Also he keeps you stringing along so you are not trying to get child support for a while anyway.

Totally agree with Fr_Chuck. He's not interested in you any more and is too much of a wimp to break up, so is holding on to you as a reserve.