First of all, you must stop blaming your 2yo for this. Try to see it as a problem that is to do with your circumstances rather than him- as indeed it probably is.
If you were not stressed by fulltime studies at the same time as looking after him and coping with a new pregnancy and planning to get married, it would probably be a lot easier to view his antics with an indulgent smile. But right at the moment you have a lot on your plate. It's not surprising you're stressed. But it's not his fault, he is just going through a normal developmental stage, it's nothing to do with your having failed to bring him up, that doesn't show itself at 2 years old.
The best thing you can do atm is to try to minimise the stress, by having a Plan.
A. Think about which tantrums you can avoid by e.g.:
giving him good warning before he has to stop an activity and think of ways to make it easier for him (e.g. wave byebye to the swings in the park)
keep tempting things he can't have out of reach if convenient
distract him as much as you can
if you are out and about, don't ignore him until he misbehaves and has to be disciplined: keep talking to him and distracting him so he doesn't have the time to get into mischief
B. Learn to recognise the triggers:
does he tantrum at a certain time of day?
during a certain activity?
when he is hungry or tired?
when you are tired and stressed and he is picking up on your feelings?
Can you do anything about those triggers? Maybe something as simple as stopping for a few minutes to have a snack together?
C. accept that some tantrums are inevitable and have a Plan for how you are going to cope when they happen. Let him work through his tantrum and tell yourself that that's ok. Have a mantra that you repeat to yourself, recite the times tables perhaps, stare into space, sing to yourself. I used to sing very loudly while dcs tantrummed: if you sing you can't shout at them at the same time and I felt I lost face when I shouted.
D. Distinguish between Giving In To A Tantrum (which is obviously bad) and Avoiding A Tantrum In The First Place (which does no harm as long as he doesn't twig that you are trying to avoid it).