It is easy to act as if hard determinism is true. Don’t treat a hard determinist decision like it is a forgone conclusion, but also don’t think of it as random (the libertarian way).

Instead, treat it as a process like any other process. Before it is calculated, you do actually have to consider the possibilities and make a real choice between them. Only retrospectively can you realise why the choice you made was necessary.

Our first person sense of free will is just our analytical capabilities. The ability to take account of circumstances and genetics in decision making and thus behave intelligently. It makes no metaphysical claims.

As a side point, in important ways we already treat ourselves deterministically, as in, whenever we say there was a reason for our actions we are attributing a suspected cause for them.

As for the responsibility thing, this mistakes what exactly makes the choice. You can’t divorce the self from the personality. If your personality caused the choice, then the self caused the choice. Just because your personality was caused by something else doesn’t pass the buck along, it’s still ‘you’ doing the actions.