Appeal to faith fallacy?

Sure but I’m not really talking about the scientific method

I’m talking about the reliability of  scientists  themselves. Should we trust them when they, for example, say that the scientific method tells us there’s climate change? Or that the pictures taken from space that show the earth is round are real?

Trusting scientists is inextricably linked to trusting common scientific knowledge they claim. If a 4-year-old kid tells us the earth is not flat, we don't necessarily trust him, but we trust the fact because of all the evidence that supports the fact of which we are well aware.

Now, if we are talking about less common scientific knowledge like the efficacy of COVID vaccines in a certain demographic, then we still need to rely on the data, not the word of the scientist. Having said that, the word of the vast majority of scientists (as in a scientific consensus ) is not the same as having faith in a person's word. It is the result of the scientific method itself.

Well I’m asking this question because currently I have a crisis of faith. I just don’t know what to actually believe anymore. Like for example if I say that so and so is true because this science book say so, wouldn’t I be doing the same as when Christians do - so and so is true because the Bible says so?

If you accepted something as correct because "this ( singular ) science book says so", I'd suggest you were making a decision based on insufficient information.  However, if you accepted something as correct because you found many references and authorities supporting the claim AND because the rationales presented in those references and authorities were reasonable and logically sound, I'd suggest that you've moved beyond simply accepting something on faith.

As an example using this site, let's consider someone asking "What fallacy is involved when .....?"

If only one person responded saying simply, "It's Fallacy X.", I wouldn't be particularly convinced.  If dozens of members of this site also responded with nothing more than, "It's Fallacy X.", I'd perhaps be more convinced.  However, I'd be even more convinced if a number of people responded by saying "It's Fallacy X because  Fallacy X involves these three things happening and the example you cited includes all of those 3 things ... and furthermore, your example also involves ... and that supports the description of Fallacy X in these ways ... ." 

My point is that accepting a claim just because "some one said so" points to a faith fallacy where the sole reason for accepting the claim is based on faith in the individual making the claim.  With more authorities making the claim as well, we have a bit more to rely on than just faith in the sole authority.  When multiple authorities agree and present cogent arguments for accepting the claim ... it seems to me we've moved beyond faith.  Or, turned around, in order to believe a claim, relying on a single unexplained source leaves nothing much other than faith; believing claims supported by multiple perspectives, solid information, and sound reasoning reduces the risk of a faith fallacy.

Well the problem with that, however, is that it’s not really practical. For instance, I just don’t have enough time or interest to study advanced physics equations just to solve some problems about physics. I also don’t have enough time to buy an advanced microscope to see protons and electrons in the atoms - I would rather simply trust that the experts have indeed observed them and take their word. That’s what I’m asking about really. So is there anything wrong with what I’m doing?

You are in luck. You don't need to do all those things. All you have to do is examine what the expert puts forth as evidence to support the opinion and see if it makes sense on its own AND check to see if other experts disagree with the first expert. Experts do not often agree, as you can see in any court trial where each side has its own experts. The alternative, of course, is simply to accept what some expert says without learning whether that expert is compromised in some manner. In short, trust but verify.