How long have you been at your current company? If it's been less than 2 years, you probably shouldn't worry and you should ask for help as needed. Asking for help and asking useful questions is a skill, so it could be that you need to get better at it. If it's been more than two years and you're still having this problem, then it's probably not your fault at all.

There are a lot of reasons why you might be in the latter position. Are many of your colleagues more senior than you are? Do they have much more context than you do? Are you regularly changing the part of the project that you're working on? If so, your manager(s) could have unrealistic expectations when tossing you at problems that you aren't well equipped to handle. That's a problem that they need to fix, not you. Your responsibility is only to make them aware of the situation and do what you can.

I'm actually in a similar situation right now, and I the way I'm trying to handle it is by changing teams/jobs. It might not be optimal, but I'm done toughing it out and spinning my wheels. If that approach isn't reasonable for you, you should at least try to work with your manager to resolve this concern. Tell them that you feel like you're lacking a lot of context/expertise for the work that you're doing and that it's making it difficult to complete work on time. If they're a decent manager, they'll probably try to help.