You said yourself that at the beginning(first three months) mino wasn't working, so why do you think it should work immediately now? It can again take a few weeks for mino to work.
Although 6 months is already big amount of time to be on any antibiotics. Are you using only retinoid as topical? You should stop with antibiotics after so many month and stick to retinoid topical and some other topical like topical antibiotic or even better BP. Of course you shouldn't use topical retinoid AND BP the same day/night, just one night retinoid, after that BP and so on. Although dermatologist can help you with schedule in my case much better was 2 nights with BP then one with topical retinoid and after that back to beginning
Dosage is good, I don't think there is a point in upping it to 200 per day, it would be an overkill.

Thanks for the response! I use 5% tretinoin in the evening and a BP/clindermycin in the morning as "spot" treatment....This has worked while on antibiotics but this past week nothing has worked which makes me think the bacteria has become resistant to the minocycline.

I also know 6 months is a while on antibiotics, and was wondering i should resort to accutane even tho my acne is moderate. Let me know what u think

Accutane is a serious business, but you can't be on antibiotics forever.
I don't know how many things you tried for your acne. I encourage to try and have some sort of journal what you eat and if it coresponds with your acne level. Important thing: if you eat something that will aggreviate your acne it doesn't need to happen like next day or two. Formation of 'pimple' is a process that can last for at least a few days. Of course diet it's just controling your acne. I will say more - for some people acne has nothing to do with their diet. But don't buy that dermatologists bullshit that acne has NOTHING to do with diet - something it do, sometimes it don't. Acne can have many causes.
How old are you? If you are younger that let say ~22 you can still hope that acne will go away naturally.
What is helping many people(me including! Moderate acne since 13 and I am now 28) is using towel on your pillow, and change towel every day(I mean okay every two days as towel have two sides). You can change pillowcases but changing towel is much easier.
All that stuff is merely for controling your acne, If you are 20 something, and you think that your acne is severe enough - talk with you dermatologist about accutane. It's serious stuff, I don't recomend it... but if you stay on antibiotics then eventually you gonna become resistant(well not you, but your bacteria of course), and you still gonna have acne.
Before accutane you can also try some potent probiotics. I would use they anyway as you were long on antibiotics, but for some people(a small minority, but I saw cases like that myself) it can help with acne. Like I said - acne has many causes. You can think about accutane and meanwhile try all other solutions to try to at least control your acne and change it from moderate severe to mild. For example I am able with all that stuff I said control my acne to mild level, and living several years with moderate acne I have to say that mild acne don't bother me(but it can be different in your case), so I don't think about accutane as it's a dangerous drug and besides... you don't have 100% certainty that it will help you long term.

BTW One more thing, if you decide on accutane course be aware of some dermatologists that prescribe tetracycline antibiotics(I'm talking about all antibiotics from that group like minocycline, doxycycline, tetracycyline, lymecycline) together with accutane to lessen initial breakout. Dermatologists like that are in minority but they happen and using tetracycline and accutane together IS VERY DANGEROUS. Using other antibiotics like bactrim(unless you have alergy to sulfa drugs) or erythromycin to deal with initial breakout is okay though and it's something to consider if you gonna use accutane and have a massive IB. Antibiotics are fine to use, but only short term

Thanks again for the help! I am an 18 year old6'2'' 158lb male who is heading off to college. I only mentioned my weight/height because i am curious if the effect of antibiotics is dependent on size (if so should I be taking stronger doses of my 100mg mino?).

Unfortunaly, diet has nothing to do with my breakouts...it's hormones. I eat healthy and have even gone to the extreme of cutting Dairy out of my diet...it doesn't work.

On a positive note my acne is not cystic, which makes me hope it will clear up and these breakouts could be a rxn to my initial "weaning" off the mino (even through I have a feeling it is not gonna get better without new treatment).

Iam seeing my derm before I leave for school and will ask her if accutane is the right option...I just hope it clears up soon because college!!!!!!

Even if your acne is hormonal diet can have influence on it. It's not always the case but I just wanted to mention that.
Weight mass is not that important when taking the antibiotics - they are working on bacteria not directly your cells. Besides 158lb(well I had to convert this to kilograms before judging ;)) is rather an average weight, and 100mg mino is an average dose. Accutane is difference - cumulative dose should be coresponding with your weight. Cumulative, so daily dose is not that important. If you decide to take accutane I would suggest to discuss with dermatologists about more modern approach - a small daily dose, but longer course. From what I understand it's much safer than shorter course but with bigger daily doses. It's not that surprising really if you drink one beer daily for five days your body gonna handle this better than 5 beers one day
You are still in age, where acne can lessen it's severity with time. So... it's your choice to take or not accutane