I've just been through a week of this and DS is 7 months next week. It was absolutely doing my head in but last night we had a solid 7pm to 7am with one wake at 3am. For us is definetly teething and also i feel like he's got to an age where he's more alert and separation anxiety is big LOL. It will pass and just knowing that there's other people out there going through the exact same thing at their age makes you realise it's not you, it's your baby it's just part of it.
Good luck and passing on the good vibes of sleep