When the original girl claims it is a mis-dx, does she offer alternative explanations? Moving 3 hours away to be with somebody you just met does sound manic. Poor judgment, impulsivity are symptoms of mania. Quitting the job also could be manic. So if she questions the dx, what does she offer instead to explain those odd behaviors?

The girl is guilt-tripping you and making you feel that it is all your fault. More frequently, in relationships, both people contribute to the good times and both people contribute to the bad times. Not always, but this is more common. So to the extent that she wants you to feel guilty, she probably should be dropped at this juncture - you do not need people intent on making you feel guilty.

The problem with the other girl is the opposite - she seems to be too enthusiastic about your getting better. This sort of over-enthusiastic involvement in your life might seem suffocating to you with time. You also might feel that you are bound to disappoint her in her expectations of your getting better if you do not get better. This might become an awkward situation. Not saying it is impossible, though.