Hi c-man welcome to DB, post all things you want to know and experience here, there are more than enough nice people here to help you out on your upcoming voyage of discovery
There's also a nice and handy search funtion, moste subjects are covered, so give it a try.
On to your question.
I think that Jimmy is on the money about your little sore feeling.
Just skip packing for a maximum hold, it's much more comfortable, and therefor you can hold longer than with packing.
Packing allong with mild streching and yoga can help you reaching your maximum lung volume filling. Wich is very handy when diving deep. Overall good Flexibility is very important to a freediver. Be carefull an go easy on streching, prefere 'often' over 'hard' training.
About your BH, have tried a BH table? Like Table A/B
http://www.freediver.co.uk/finalsite/dsbolt/satt/satt.htm
About the BH/static resulds, I find that a beginner often goes to a "maximum" within a few months in terms of time. After that he/she flattens out her maximum BH times. This can be frustrating for some after getting used to a PB every week or training, and they often train harder, try harder etc. This harder training does not give the results, they only got worse!
I think that static training is a very delicate thing, and one should try to learn ones body instead of improving on time. Do a maximum effort only once or twice a month.
Currectly I practice 2 Co2 schedules (Table A) a week, and one Table A/O2. Be sure to read the directions carefully and follow them, though I know it's very tempting to 'level up' often.
Learn feeling your body and check your knowledge once or twice a month in a max, only if you feel like it offcause.
Another thing helping your static is your overall stanima/fitness level. Running/cycling/swimming etc.
And it's much more fun if you find youself a training partner/buddy. He/she can give you directions and be your safety.
Talking about safety, if you don't have a competent buddy don't do wet training. I recomment you and also your buddy to follow a freediving course, this way you'll gain much insight, learn about safety, techniques, and much more.
Fun and safe diving,
Kars
