K.H.
Not sleeping through the night is completely normal for 6 month old. There are many different things you can try to help, but in reality, it may not happen for a while. The best thing is to find some things that work for you and make a plan and stick to it 100% for a long period of time. Get a strict routine. Chances are that he's just hungry so you'll still have to feed him, but if you get a routine down you should be able to just BF him and put him right back to sleep and minimize the amount of time you're awake. I think my daughter stopped BF in the middle of the night around 9-10 months.
Get the book "no cry sleep solution". It's not a miracle book but the main focus is to help you set up a solid routine and cut out anything that hinders him sleeping for longer periods of time.
Oh, and I would suggest rather than giving him breastmilk in a bottle with cereal to JUST GIVE HIM CEREAL OR FOOD. There is no reason to put it in a bottle! Just give him a small portion of cereal just before bed if that helps him sleep. Like a bedtime snack so to speak. It might help and it will give him some practice for eating too! :)