K.G.
it definatly sounds like tummy trouble to me. have you tried the mylacon drops? i lived by those.
i read , and we all know about "they", but "they" say that it is impossible to spoil a child under 1 yr of age because they only know needs to that point. I dont know if that is true but I certainly believe it and I most certainly believe that at 5 months they are not capable of manipulation.
and if this isnt because of tummy troubles it may just be a security thing. its ok to hold your baby many hours of the day if that is what they need. i think sometimes people focus on babies and chilrens needs like food shelter clothing safety but forget that security is an actual need.
when mine were at the stage of crying when in bed i would give them no more than 15 min to cry. i knew after that then they were not going to comfort themselves and needed a parent.
i think you are handling the situation fine.
good luck and cross my fingers it isnt medical and you'll all get through it.