...and all those incompatible tankmates held within a two and half foot tank? Really?? And you still want to add more to the pot?
Or is this a little wind-up?
If it's true then I can only suggest you (i) rehome the sharks (I note the plural there, so you obviously have more than 1 which is a definite no-no anyway - and any of the shark family are not suited to that size tank with other tankmates as they are territorial and will chase and bully other fish - if they're not doing it right now, they will when they mature); (ii) rehome the convict (same as for the shark, they are territorial and will chase/bully etc and the tank is a bit small for their fully grown adult size); and (iii) that will leave you with the Betta...
There aren't that many fish you can choose to house with a Betta. So, unless you want a fairly empty tank with just a betta and maybe some Ottocinclus, or cories, you might want to rehome the betta and start completely afresh. If you're unsure about fish compatibility, ask on here before you buy anything.
Or is this a little wind-up?

If it's true then I can only suggest you (i) rehome the sharks (I note the plural there, so you obviously have more than 1 which is a definite no-no anyway - and any of the shark family are not suited to that size tank with other tankmates as they are territorial and will chase and bully other fish - if they're not doing it right now, they will when they mature); (ii) rehome the convict (same as for the shark, they are territorial and will chase/bully etc and the tank is a bit small for their fully grown adult size); and (iii) that will leave you with the Betta...
There aren't that many fish you can choose to house with a Betta. So, unless you want a fairly empty tank with just a betta and maybe some Ottocinclus, or cories, you might want to rehome the betta and start completely afresh. If you're unsure about fish compatibility, ask on here before you buy anything.