I feel crazy!

I am 17 weeks and 3 days. This is my third pregnancy and I feel like I am going crazy.

I feel like I should be feeling my baby more or at least confident that I am feeling him and not gas bubbles.

I feel worried constantly that I'm not eating the right things.

I feel like my cold has effected my baby.

I feel like my taking Tylenol and melatonin and Claritin is going to effect my baby.

I don't know if this is because I'm 8 years older than my last pregnancy or what is going on.

Does anyone else feel this way? Please share some encouraging thoughts and wisdom. It's a long three weeks until my next appt and 23 weeks is a long time until I meet this little baby bump.