vehicle will start when put in drive and when put in reverse starter engages and also the ignition wont start vehicle sometimes and the o/d light blinks when driving down the road

 

if anyone can help me i would very much appreciate

 

The DTR switch (on side of transmission) is likely faulty.
The OD light flashing is telling you of the issue.
The DTR normally does not permit cranking the motor in any position but Park or Neutral for safety reasons.
Have the code read. The code description should also tell you the same information.
Good luck.