Should I still pursue learning in my forties?

How about take a look at skillsfuture website? There are alot of useful information.

Eg You can apply for the skillsfuture studyawards. The award pays $5k. For early to mid career singaporeans who meet the requirement in various industries. http://www.skillsfuture.sg/studyawards

For singaporeans 40 and above, I quote " Eligible individuals will receive higher subsidies of up to 90% of course fees (See Table 1.) for over 8,000 SSG-supported courses with effect from 1 October 2015, and at least 90% of programme cost for MOE-subsidised full-time and part-time courses ranging from Nitec to postgraduate1 level in the following institutions for course semesters commencing from 1 July 2015. "

With that u can look for available course of your interest, eg in a local polytechnic

http://www.skillsfuture.sg/enhancedsubsidy

From what u have written, it gives me a feeling that u are experiencing burnout from your current work. Maybe u are just looking for a break? Even if the courses are free, would u still have the energy to attend them, and do the assignments ?

It's never too late to learn new stuff, but w your current commitments you might need to prioritise. If it's sth that helps you become better at work, are there grants, sponsorships or scholarships which could help you financially and perhaps improve your career prospects?