Desperate Need of Advice

My 02 trailblazer has been having issues ..about a year ago I went
to the store everything was fine no issues nothing ..after I walked
out the store I got into my truck went in reverse backed out my
parking spot and put It in drive and nothing ..I hit the gas it just
creeped forward and reved up as I hit the gas ..I felt the tranny
engage when I put it in drive so I bealive it was n gear because I
was being pulled forward (Flat Surface)..after I sat there reving it
up it  finally what I would describe as.. caught?? Or jumped in gear
wich wouldn't make sense because it was already in drive I felt
the truck go into drive when I shifted out of park and it pulls
forword..but after it finally started working again I drove off and
never had a issue this was about a yr and a half ago ..iv since
drove the truck thousands of miles ..and suddenly this issue
reared it's ugly head again ..wife was driving yesterday and she
was going about 25 mph and she said it felt like she ran over
somthing ..thought she might of had. Flat tire ..she noticed when
she hit the gas the truck would just slowly coast forward..it finally
kinda jerked and started working ..she came home about 5 miles
away and it drove fine she said she heard a weird noise when she
got to 45 mhp and when she got here I got into it and went to
work as I got to 45 mph exactly I hear the noise sounded like it
came from the rear driver side like a loud funneling noise maybe a
whinning noise bit it was very very faint I set the truck on cruise
control and 2 min later I felt like I ran over somthing truck kinda
sputterd a bit and I slowed down ..once I got stopped I put it in
drive I felt it engage and I hit the gas and nothing happen it just
reved up and slowly pulled forward tried reverse and it kinda felt
like it didn't wanna pull in reverse as if it went in gear but it was
like I was trying to back over a curb ...so I put it in park and after 5
min (waiting on tow truck) I cut it back on and it was sorta of a
delay when I turned my key over but after I hold the key on ON
position for a second or two it cuts on and idles at like 2 (usually
idles at like 1) it sounded like I was pushing the gas and at the
same time it was bogging out sounded like total crap....wich had
never happend ..I cut it off it did the same for a couple more times
then it didn't do it any more ..after it got towed home (wasn't a flat
bed he used a Boom) he dropped it on my drive way I got in put it
in reverse and it backed into my drive way fine no issues ..I drove
it around the block only hit like 35 tho (kinda scared) and there
was no issue made a funny noise under it like a funneling but it
was few and far between ..and I noticed my cruise control don't
work anymore..I've never had any issues with the truck like this
it's a 02 4wd 170 k miles I've check the fluid everything is good
don't smell burnt or look dark ..no check engine light at all ..I've be
had issues since I bought it though sometimes it idles low and the
truck vibrates while your stopped or in park  and kinda idles low
and vibrates. . never cuts iff tho...and the vibrations get heavier as
I turn the wheel or cut the heat on or ac ...if you can help with
advice it would help me alot as I'm trying to sort this out its my
only vehicle.ive changed the 02 sensor the one beside the motor
already