I moved your post to this forum, you should get more help here. From my unprofessional thoughts, not being able to build pressure implies: running out of water, a break, leak, or split in the pipe, or a bad pump. Probably other reasons...hopefully the pros can help.
My feeling, trying to pull a pump from that depth for a novice is not something you should try. Depending on how deep the well actually is, and the current depth, and recovery rate, they may be able to lower it. I think it's time for a pro.