Yes, you can put the vertical base antenna on the same pole as your TV antenna, especially if you have several vertical feet between them. Your TV antenna is probably a log periodic antenna, which is directional and covers a different band.
I would try that first. If you don’t watch TV while you’re transmitting you probably won’t even know it. If you do transmit while someone is watching TV, run some tests to see if they get any interference. Make sure the mast is grounded.
If the attic is much easier try that, but getting it higher makes more difference than having more power.