First of all I am a girl that knows "not too much" about car repairs but I have to do something about this problem. You all seem so knowledgeable about this stuff, I am looking for any ideas at all...

About a month ago i noticed that my jeep sounds real loud when i am getting to about 40-50 mph. Almost like tire noise but it isn't. It almost seems like it doesn't want to go into O/D. If i take the tach to 4000 rpms it does shift, and it drops to about 2000 but i still here this loud noise..almost a vibration sound. I know something is wrong but I can't pinpoint it. What I do know is my passenger side CV is blown. And there is sometimes a strange noise i hear at about 35mph coming from that side..it seems to come and go..I think that must be the cause of that. But back to the tranny issue i wanted to mention that when i let off the gas the RPMs drop real real fast..faster than i remember them prior to this problem starting. I must admit my maintence on this tranny hasn't been up to par. I also noticed that at an idle in park it seems like it wants to miss or something..in neutral it sounds normal but at in anything other than neutral it sounds real "rough" ..i guess it would be called a rough idle. My boyfriend is screaming "u joints" but i don't know..Im thinking maybe the bands need adjustment but when i looked it up in the book i have it sounded very complicated. My money is very very low..and I am just hoping there is something I can do myself(or have a friend do) that might remedy this problem. If it is the bands can someone tell me how to do it?.
my jeep has 105 thousand miles on it..just fyi...
any ideas about where to start will be greatly appreciated.
I know that this is a full time 4wheel drive and i have a feeling I may live to regret buying this jeep. Ive had it for five years and it has really had no problems. So....all of you wonderful people out there...any ideas????
thanks in advance!