Divorce Source: onesided mediator

We really could use some advise...it's been 2 years now since all of this started (step sons visitations)we've already gone through a GAL but she was leaning more towards us on having joint custody of our 6 year old (now)...but his mom didn't like what the GAL had to say...so now we are going through a visitation expediter, and from the first time we had to go to her until now, we've had to defend ourselves over and over again...(exp.)on the first mediation the med. came in after talking to the Ex, told my fiance she wanted him to answer a question, but this question couldn't be answered with a yes/no, so he started to tell her his side of things, She(med) stoped him and told him that "He was one of the that when you ask for the time they tell you how to build a watch then said she only wanted a yes or no...And it's gone down hill from there. The med. has been name calling, threatening with taking visitation away, accusing us of doing things wrong, because we feel the need to Defend ourselves....She takes the EX's word as gold, she sends us letters stating that the EX said this or that or saw this or that and what ever we're doing wrong had better stop now...and we never get the chance to tell her what actually happened while our 6 year old was with us...
Right now we get every TUE, THURS, for 3 hours each day and everyother Fri,Sat. She's also made a point of making us feel unworthy to ever be around any children. We do have 3 other children as well,15 boy 14 girl 10 girl, the 2 oldest are mine and the 10 year old is my fiances from a previous marriage.
Our lawyer also seems to think that this case is not worth his time cause he seems to not want to get back to us...This has been a complete strain on all of us and the stress level is way beyond where it should be...Please does any one know what we can do to put all of this to a stop before she makes a point of us never seeing our 6 year old again...
We went through a judge on the first day of mediation, the second time was just us (no lawyers) in the town court house, and from then till now there has been emails passed back and forth as advised by our med.
Also, the second meeting we had she made a point along with the EX to attach everything we had to say, demanded that we keep our mouths shut while the other party talked yet the other party could interupt us while we were talking...This lady has been a night mare for us...I thought the whole reson for having a med. was to make things go smoothly, no stress, and take BOTH sides into consideration...
WE don't know what to do anymore, we don't know what we CAN do anymore..My fiances affraid to go after her and make a report cause he thikns it's going to turn around and land on us....Please if anyone has any thought on this we are totally open for anything....