4th dwi, how long can i xpect to serve on a 7

[GoingtoMoDOC]

Hello everyone,
to give you some history ive had 4 dwi's all spread out over 10+ years, however i am still on probation for the 3rd when i got the fourth. i did a 120 treatment in farmington a few years back and now face my backup plus new sentencing up to 7 years for the fourth. Im extremely nervous about the whole ordeal because ive had friends that went to doc say youll get a 15% serve time, but im reading on these forums and it seems far from it to me. realistically how much time can i expect to serve? ive always been a model probationer untill this first violation. will my previous 120 treatment hurt me in this scenario as far as minimum time needed? i would really appreciate any input from anyone having experienced dwi's in missouri doc. also if it helps, my therapist and myself believe bad military experiences to be the factor of some mental issues and the drinking was self medicating, will this have a negative impact on my parole eligibility? im just really freaking out here a bit, ive heard expect to serve half of it .. all the way too youll barelly make it out of diagnostics. please help me get some peace of mind with a little awareness of your experiences.. thank you all in advance.. miller.