> I'll talk to him to know if they still want me there.
Why would you think they don't want you there? This is not a helpful mindset to have. Here are the facts:
1) You passed the interview process.
2) They made you an offer.
3) They've continued to invest in you as an engineer by giving you feedback on your weak spots and where you can improve.
If you were really that far behind, they would have realized that in the hiring process and you would /not/ have received an offer. So let's start there. They definitely still want you there. That is why they hired you.
Second, let's talk about your "lack of knowledge," "being behind some things" and "real world experience" that "slapped [you] in the face" -- based on your mindset it looks like you are viewing this as a negative, or as proof of failure. Why is that the case?
You have 10 years of experience solving problems and getting paid for it. Now, you are solving different kinds of problems, so you're developing new muscles. It's expected on their end (and should be expected on yours) that there is some kind of /ramp up/. Talk about what ramp up means. Figure out your manager's expectations, and figure out what resources you have available to engage in ramp up. I guarantee you this, there's ramp up at any new medium-big company anywhere you go. There's tribal knowledge, spinning up on the industry vertical, etc -- all of this is incompressible, doesn't matter how good of an engineer your are.
If your manager is any good, they likely know about this and will appreciate you being aware of this problem as a logistics problem, not a moral problem. So think about it that way. Stop thinking about "whether they want you there" -- start thinking about "what blockers are in your way towards being productive" and start building a game plan with your manager. Worst case scenario, you're not able to accomplish it, but at least you gave it an effort and approached it the right way. That's a much more mature, proactive and effective approach than self-sabotaging yourself with feelings of inadequacy. I have a hunch that you won't fail if you do this, though. Just thinking about what you want to get accomplished and the nitty gritty details of how you get there and collaborating with your manager to get to a plan you're both happy with is /a lot/ of work -- once you've done that, if you work at a functional organization, the chances of you succeeding are very high!
Give yourself a pat on the back, while you're at it. Getting to a point where you're still being challenged after 10 years of experience is a /good/ thing! It reflects well on you and indicates your desire for growth. In all likelihood, your company saw this motivation in you and that's why they hired you. Look at the positives and opportunities here, and I'm sure you'll do amazing.
Good luck!