Michelle, I'm sorry you're so tired
I can relate. The thing is, once a night isn't too bad comparatively.
At 22 months my DD will occasionally wake once a night too. I sit next to her cot and I pat her bottom til she goes back to sleep. It takes around 15mins to half an hour.
There are loads of things you can try (and I'd thoroughly recommend a bedtime routine too - books are lovely, perhaps a song, a snuggle, say the same words each night etc etc - all very comforting for your little one), but at 7.5 months I'd suggest preparing yourself for the possible reality that he's pretty darn normal, KWIM? Many people (including my GP) have told me that their babies didn't consistently sleep through the night til they were close to or over 12 months.
Don't mean to depress you, but honestly, while I know you are soooooo tired (I am still there some days!) he will grow very quickly and it will all be behind you before too long.
again. Hang in there, mate!