Cant overfeed a b/f baby hon...so put that query to rest....
What you and your DS is doing sounds perfectly normal to me - my DS is 7 months, and last night we were up every 2 hrs......for boob..... Usually he will do 3hourly feeds. We're fully onto solids too , and this has not decreased the night feeds.... I would say its comfort sucking, bit more of mummy in the night etc etc.
Can you pop him into bed with you ??? I find around the 4am feed - where ive already been up twice, i cannot keep my eyes open, i pull him into bed with us...give him a feed......i doze off, and so does he....

GL....i know the sleep depo is hard.....but it will pass. They go thru a growth spurt at 6-7mths too...maybe he's climbing that mountain at the moment.....