I’m going to make a few guesses for the following reasons.
I’m not sure I’m smart enough because I’m not progressing (fast enough)
You might think you’re not progressing because you keep forgetting words, or you (still) can’t make sense of what you’re listening to.
First, realise that it’s entirely normal to forget words, either how to spell them or what they mean or both. Forgetting is part of the process of learning. If you’ve forgotten the word recently, use that forgetting as an opportunity to try and recall what the word means. If you haven’t seen the word in weeks, then it probably wasn’t that frequent anyway.
If you can’t make sense of what you’re listening to, again, realise that’s perfectly normal early on. First, try to listen
The key point here is that you should assume that what you’re feeling has been experienced by at least some, if not most, of the language learners out there. This is the act of normalising your experience, so that you don’t feel like you’re all alone.
I’m not sure I have the time
There’s likely two reasons why you feel you don’t have the time. Either you haven’t made language learning a habit yet, or you haven’t found a motivating enough reason to learn the language.
When I say ‘make language learning a habit’, it doesn’t have to be major steps at first. It can be as simple as trying to remember one word a day. It can also be as simple as logging on to whatever website you’ve decided to use and using its features for 5 minutes… or 1 minute… or 5 seconds, however little it takes to think “that’s a small amount of effort, I don’t mind doing that”. You might find yourself getting sucked into language learning!
If you don’t have a motivating reason, it’s ok to give it a pause and try a different language. This might be bound up with feelings like guilt, perhaps because you’re Chinese and think you should be able to speak the language. To remedy this, remember that you are partially a product of circumstance.
For example, Singapore took aggressive steps to promote English as the first language, and your lessons in Mandarin/Tamil/Malay may have seemed to you pointless. Language learning might have seemed to be something that you did to get grades.
I propose that you take your time to explore cultural or other aspects of the target language. For example, learn the history of the target language.