Parenting & kids - Please help! I am afraid of giving my baby food

My baby has been always gassy. She is both breast and formula fed. ( I
don't have enough milk for her. I tried herbs and pumping, nurse her
often ) We tried all different formula and it didn't seem make
difference. Unfortunately she didn't take hyperallergenic formula at
all because it tasted awful. I eliminated all dairy from my diet. When
she was little, she cried until 11:00pm. But when she went to bed, she
always has been able to sleep for 6 or 7 hours straight.

Just before she turned to 6 month, we started solid, rice cereal and
sweet potato. The first one week, it was great. She seemed having less
gas and slept great! But the nightmare started the day she had her
immunization shot. She is 7 month now and the last month, she has been
waking up by gas almost every hour before midnight. We usually put her
to bed at 7:30. A couple of hours after she eats, her tummy starts
making noises, like fireworks. After midnight she seems to be better.
I guess that is because all food has been already digested. Since she
wakes up so often, she is hungry again. She is teething now, but it
doesn't seem bother her that much to me. I tried rice cereal, oat
meal, barley, none of them seem improve the gas problem. I am at the
point that I am afraid of giving her food.

I don't think immunization shot could cause this. It might have
irritated her tummy. But it has been a month and it is not getting
better. Is it possible she is milk intolerant or has problem with her
digest system, or anything else? I has been hoping her tummy gets
better when she gets older. But she is 7 month now, and her tummy is
still so weak.

Anybody can give me some ideas or suggestions? It is very appreciated.